a baby: a human being at the very start of life, whether still in the womb or newly born
TranslatabilityApproximateCertaintySettled
This word marks the earliest stretch of a human life. Luke uses it of John while Elizabeth is still carrying him, and a chapter later of Jesus lying in a feeding trough, without reaching for a different word: one term covers a child before birth and a child a few hours after it. Wherever it appears, the person named is small, newly arrived, and wholly dependent on somebody else.
Greek had several words for the young, and they divide the ground differently:
the general word for a young child (παιδίον) reaches from a newborn up to a boy or girl old enough to walk and play
the word for one too young to speak or reason (νήπιος) is often turned into a picture of an immature believer
the ordinary word for a son or daughter (τέκνον) is about relationship rather than age, and fits a grown child as easily as a small one
Once the word does not name a person at all but a starting point. Paul tells Timothy he has known the sacred writings "from infancy", reaching back as far as a life goes. That is the same instinct at work: this is the word for where a human being begins.
Nuances
1aa child still in the womb
Luk 1:41Luk 1:44
1ba baby: a child newly born or still at the breast
Luk 2:12Luk 2:16Luk 18:15Act 7:191Pe 2:2
1cinfancy as the earliest point a life can be traced back to, in the phrase "from infancy"
reaches back before birth: it is the word for the baby still being carried, the one that kicks inside Elizabeth when Mary greets herLuk 1:41Luk 1:44
the plain word for a just delivered newborn, the baby the shepherds are told to look for, wrapped up and lying in a feeding troughLuk 2:12Luk 2:16
stays on real babies and real infancy: the newborns Pharaoh had put outside to die, and the age from which Timothy had already known the sacred writingsAct 7:192Ti 3:15
Both
both picture the very young by what they can eat, milk and not solid food, and both turn that picture on people who are new in the faith1Pe 2:2Heb 5:13
both can point at actual small children, the babies people carried to Jesus so he would touch them and the children whose praise Jesus quotes back at the priestsLuk 18:15Mat 21:16
works as a label for grown people who have not grown up, and it stings: Paul can speak to the Corinthians only as beginners in Christ, and the confident teacher in Romans casts everyone else as the untaught1Co 3:1Rom 2:20
comes with the expectation that you leave the stage behind: childish talk and thinking get put away, and believers are told to stop being tipped over by every new teaching1Co 13:11Eph 4:14
can describe a legal position rather than an age: the heir who owns the whole estate is still no better off than a slave while he counts as a minor, and Paul says believers once lived under that kind of tutelageGal 4:1Gal 4:3
can also be a compliment: the simple and unimpressive are exactly the ones the Father lets in on what he has hidden from the wise and cleverMat 11:25Luk 10:21
τέκνονa son or daughter named by relationship to a parent, at any age
Reaches back before birth: it is the word for the baby still carried in the womb, as when Elizabeth's unborn child moves at the sound of Mary's greeting.Luk 1:41Luk 1:44
Fixes on the newborn stage itself, the child who has just arrived and can do nothing for himself: the sign given to the shepherds is a baby wrapped in cloths and lying in a feeding trough, and Pharaoh's cruelty is aimed at babies too small to survive being put out.Luk 2:12Luk 2:16Act 7:19
Because it names an age rather than a bond, it can mark the earliest point on a person's timeline, often rendered "from infancy", and it can supply the picture of a beginner still living on milk.2Ti 3:151Pe 2:2
Both
Both name a real living young human being, which is why English Bibles can say "children" or "babies" for either one.Luk 18:15Mat 2:18
Both show up where a parent's hope or grief for the little ones is the point of the scene.Act 7:19Luk 23:28
Names the tie to a parent rather than an age, so it covers grown offspring as easily as little ones: a father sends his two working-age sons into the vineyard, and the law about a dead brother is about leaving offspring behind.Mat 21:28Mat 22:24Eph 6:1
Stretches down a whole family line, so an entire people can be called one ancestor's children centuries later.Mat 3:9Jhn 8:39Rom 9:7
Carries the standing believers are given before God, who are said to be born of him and named his own.Jhn 1:12Rom 8:161Jn 3:1
Serves as a teacher's word for those he brought to faith, addressed with a father's affection and authority.1Co 4:141Ti 1:2Phm 1:10
Labels people by whatever shapes them, so a person can be called a child of a quality or a condition rather than of a parent at all.Eph 2:3Eph 5:81Pe 1:14
This is the plain, ordinary word for a baby, and it covers the whole earliest stretch of a life: the child who stirs inside Elizabeth before he is born (Luke 1:41), the newborn lying in a feeding trough (Luke 2:12), the infants parents carry to Jesus (Luke 18:15), and even the first remembered years of a person's life (2 Timothy 3:15).Luk 1:41Luk 2:12Luk 18:152Ti 3:15
It always names a living child, which is exactly what makes harm done to one so terrible: Pharaoh forced the Israelites to abandon their babies so that they would not stay alive (Acts 7:19). The word itself says the child is alive; the cruelty is in what is done to him.Act 7:19Luk 1:44
It belongs in warm, everyday scenes of care and can be used of a baby without any comment on the baby's worth: shepherds find the wrapped-up child (Luke 2:16), parents bring their infants to be touched (Luke 18:15), and a newborn cries for milk (1 Peter 2:2).Luk 2:16Luk 18:151Pe 2:2
Both
Both words look at the very beginning of a human life and picture what comes out of the womb: the child moving inside his mother before birth (Luke 1:41), and the birth that ended before the child could live (1 Corinthians 15:8).Luk 1:411Co 15:8
Both are also used as comparisons for the condition of a believer rather than for a literal baby: Christians are told to crave God's word the way a newborn craves milk (1 Peter 2:2), and Paul likens himself to a failed birth before God's kindness reached him (1 Corinthians 15:8).1Pe 2:21Co 15:8
This word does not name a child who lives at all. It names a pregnancy that ended too early, what Greek writers and doctors called a miscarriage, the thing expelled from the womb before it could survive. Paul uses it once, saying the risen Jesus appeared even to him, as though to such a birth (1 Corinthians 15:8).1Co 15:8
It is a shocking word, chosen for its shock, and it is aimed at the speaker himself rather than at any actual baby: Paul puts himself at the very bottom of the list of witnesses with it, and in the next breath calls himself the least of the apostles, unfit to be called one (1 Corinthians 15:8). Nobody would reach for this word as a plain label for a child.1Co 15:8
Its background is the grim Old Testament picture of the birth that never came to life, where such a birth stands for horror and for a life better never begun. That shadow of lifelessness is what Paul pulls over his own past as a persecutor, so that everything he became can be credited to God's kindness (1 Corinthians 15:8).1Co 15:8
brephos in the other biblical languages
עוֹלֵלHebrew“infant”the Hebrew word for a small child or nursing infant, usually named among the most defenseless people in a city
Covers the whole span from before birth to a child carried in someone's arms: the baby still inside the mother (Luke 1:41,Luke 1:44), the newborn wrapped and laid in a feeding trough (Luke 2:12), and the babies people brought up to Jesus (Luke 18:15). The Hebrew word is only ever used of a child already born and still nursing.Luk 1:41Luk 1:44Luk 2:12Luk 18:15
Works as a marker for the starting point of a person's life rather than as a description of an actual baby. In 2 Timothy 3:15 the phrase is rendered "from infancy", dating how far back a lifelong habit reaches.2Ti 3:15
Both
English Bibles reach for the same two words for both, "baby" and "infant", so a reader meeting the newborn of Luke 2:16 and the little one of Isaiah 65:20 sees one English word standing over two different original words.Luk 2:16Isa 65:20
Both picture a person with no say in what happens next, entirely in the hands of the adults holding it: babies carried to Jesus by other people in Luke 18:15, and the child whose survival depends on its mother in Isaiah 49:15.Luk 18:15Isa 49:15
Both turn up where the fate of the very young measures the world a child is born into: infants put outside to die under a hostile king in Acts 7:19, and the promise that no baby will die after a few days in Isaiah 65:20.Act 7:19Isa 65:20
Names the child a mother is still feeding, so the nursing bond sits inside the word itself. Isaiah 49:15 can ask whether a woman could forget the baby at her breast without adding any further description. The Greek word needs help from other words to say the same thing, which is why 1 Peter 2:2 has to add "newborn" and "milk" alongside it.Isa 49:15
Can be tied to a count of days to picture a life that ends almost as soon as it starts, as in the promise of Isaiah 65:20 that no baby will live only a handful of days.Isa 65:20
What scholars say about brephos
The standard lexica treat this as a single noun covering the human being at the beginning of life. BDAG separates an unborn child (Luke 1:41, 44) from a newborn or very small child (Luke 2:12, 16; 18:15; Acts 7:19;1 Peter 2:2), and files the adverbial ἀπὸ βρέφους (2 Timothy 3:15) as an idiom for "from infancy"; Liddell-Scott-Jones records the same range in wider Greek, where the noun can also serve for the young of animals. Commentators on Luke regularly note that he writes βρέφη at 18:15 where Mark 10:13 has παιδία, sharpening the age of those brought to Jesus, and that the infancy narrative applies one term on both sides of birth (Fitzmyer, Bovon). Whether the prenatal and postnatal uses constitute two lexical senses or one referential range with contextual shading is a lexicographic judgment about how finely to divide, not a live disagreement about what the word denotes.
Sources
BDAG, s.v. βρέφοςlexicon
Liddell-Scott-Jones, A Greek-English Lexicon, s.v. βρέφοςlexicon
EDNT, s.v. βρέφοςdictionary
Joseph A. Fitzmyer, The Gospel According to Luke I-IX, Anchor Bible 28 (Doubleday, 1981)commentary
François Bovon, Luke 1: A Commentary on the Gospel of Luke 1:1-9:50, Hermeneia (Fortress, 2002)commentary