to fall into a heavy, sunken sleep: a deep stupor that shuts down the senses, often sent by God
TranslatabilityApproximateCertaintyStrong
This is not the ordinary word for rest. When the Hebrew Bible means a normal night's sleep it reaches for other verbs; this one is held back for a sleep so heavy the sleeper is past reach, senses closed, unable to stir or respond. It always pictures someone dropping under, never a light nap.
The same deep sleep turns up in very different settings, which is why English translations reach for different phrases. It can be plain exhaustion, as when a hunted soldier collapses; a deathlike stillness God brings over an enemy army; a shameful stupor of laziness at harvest time; or the overwhelming faintness that falls on a person standing before an angel.
What holds these together is helplessness. In this sleep a person cannot act; things happen to them rather than by them. That is why later Greek and Jewish readers linked the related noun with trances and visions, and why the word carries a weight that a plain "sleep" would miss.
Nuances
1ato fall fast asleep: to drop into a heavy sleep from exhaustion or the weight of the moment
Jdg 4:21Jon 1:5*Jon 1:6
Jon 1:5
Whether Jonah's sleep in the hold is ordinary heavy sleep or a trance-like torpor of the kind the word carries in visionary settings.
majorityOrdinary heavy sleep, the exhausted or morally numb slumber of a prophet fleeing his commission, part of the story's repeated pattern of going down.; James Limburg, Jonah (OTL, 1993); Douglas Stuart, Hosea-Jonah (WBC 31, 1987)
minorityA trance-like torpor, playing on the wordplay of going down and the parallel to visionary deep sleep elsewhere in the Hebrew Bible.; Jack M. Sasson, Jonah (Anchor Bible, 1990)
1bto be sunk into a deathlike sleep: stilled into helplessness, next to death itself
Psa 76:6(7)
1cto lie in a shameful stupor: figuratively, to be sunk in laziness when one should be working
Pro 10:5
1dto be overcome before a divine presence: to fall into a faint, senseless stupor when an angel appears
A deep, heavy sleep so profound the sleeper is dead to the world and to danger around him, whether from exhaustion or laziness.Jdg 4:21Jon 1:5Pro 10:5
An overpowering stupor that falls on a person and knocks them out, a collapse into unconsciousness rather than a rest they lie down for.Dan 8:18Dan 10:9Psa 76:6
Both
Both name the plain fact of being asleep: a person at rest, eyes shut, no longer aware of what is going on around them.1Ki 19:5Jon 1:6
The ordinary, peaceful sleep a person chooses at the end of the day: lying down and resting through the night, often as a picture of safety and trust.Psa 3:5Psa 4:8Ecc 5:12
Sleep used as a gentle picture of death: a rest one does not wake from, the sleep the dead are said to lie in.Jer 51:39Jer 51:57Psa 13:3
A further stretch of the word to things that have grown old or stale with time, like stored grain kept over or a long-standing skin disease, a sense the other word never carries.Lev 26:10Lev 13:11
נוּםto doze or grow drowsy; a light slumber, the opposite of this word's total heaviness
Names sleep so heavy that the sleeper is completely helpless, whether a commander who never stirs while he is killed in his tent or a passenger who sleeps on through a storm that has hardened sailors crying out.Jdg 4:21Jon 1:5
Describes a stunned collapse in the presence of something overwhelming, a state the person cannot come out of until someone touches him and sets him on his feet.Dan 8:18Dan 10:9
Used of sleeping straight through the hours when the work has to be done, which marks the sleeper as a disgrace rather than merely tired.Pro 10:5
Both
Both name the sleep of beaten warriors, and they stand side by side in one poem: the brave sleep their sleep and cannot lift a hand, and horse and rider sink down and do not rise.Psa 76:5Psa 76:6
Both can carry blame, naming sleep that leaves a duty undone while danger is already at hand and someone else has to raise the alarm.Isa 56:10Jon 1:6
Pictures the first drifting off, a heaviness in the eyes rather than dead sleep, which is why it fits a watchman who is still at his post but no longer alert.Isa 56:10Nam 3:18
This is the word the Bible uses of God, and only to rule it out: the one who guards Israel never once nods off, day or night.Psa 121:3Psa 121:4
Serves as the measure of readiness in an army on the march, where not a single soldier lets his attention slip.Isa 5:27
שָׁכַבto lie down; it names the posture of reclining, while this word names sinking into unresponsive sleep
radam in the other biblical languages
κοιμάωGreek“to sleep”the everyday Greek verb for falling asleep, also a gentle term for dying; it overlaps the deathlike-sleep sense but lacks the imposed, senses-shut-down force
ἔκστασιςGreek“amazement”the Greek word for a trance that the Greek Old Testament chose for this root's God-given sleep; it captures the visionary stupor of the Daniel scenes but not the ordinary or deathlike uses
Describes ordinary, heavy physical sleep, a person so soundly asleep that they are hard to rouse, sometimes through sheer exhaustion and sometimes through blameworthy carelessness. The Greek word never means literal sleep.Jdg 4:21Jon 1:5Pro 10:5
Both
Both can describe a person overtaken by God into a state that removes them from ordinary waking control during an encounter with the divine: the deep sleep that falls on a prophet as a vision comes, and the trance in which revelation is given. The person is not acting or perceiving as usual, but is held by God for the moment of disclosure.Dan 10:9Dan 8:18Act 10:10Act 22:17
Names the overwhelming amazement that seizes onlookers when they witness a miracle, a rush of wonder mixed with fear as people react to God's power. The Hebrew word never carries this sense of astonishment.Mrk 5:42Luk 5:26Act 3:10
What scholars say about radam
The verb occurs seven times, only in the Niphal, and the standard lexica agree it denotes an abnormally heavy sleep rather than ordinary rest: HALOT glosses it "to lie in a drugged sleep" (Betaeubung), and the 18th-edition Gesenius uses Tiefschlaf/Erstarrung (deep sleep, stupor). BDB (p. 922) sorts the verb under three heads: being fast asleep (Judges 4:21;Jonah 1:5-6; Prov 10:5), the sleep of death (Ps 76:7 MT = 76:6 English), and the stunning effect of awe (Dan 8:18; 10:9). TWOT (#2123) stresses that the cognate noun almost always refers to a supernaturally induced sleep. There is no dedicated article in TDOT or TLOT; both treat the root within the synoptic entries on yashen, noting it marks the deepest, often divinely imposed sleep. Comparatively the sleep sense is nearly isolated in Semitic; the one serious external anchor is Arabic radama, "to block up, stop up, bury" (Lane, s.v.), which if genuine suggests an underlying image of the senses being walled up, though HALOT and Gesenius flag it only as a comparison and DCH declines cognates on principle. The Septuagint's differential rendering of the fourteen verb and noun occurrences, notably ekstasis in Genesis and katanuxis in Isaiah 29:10 (taken up by Paul in Romans 11:8), shows that ancient translators already read the word as marking a God-imposed altered state, not a normal nap.
In-depth research
This is a research paper, so it may be hard to read without scholarly background. It is useful if you want to dig even deeper into this word.
Sources
Brown, Driver, Briggs, A Hebrew and English Lexicon of the Old Testament (1907), p. 922lexicon