cheilos

Greek uses this word for the two soft edges of the mouth, exactly as English does. What makes it worth a second look is where it turns up: every New Testament use of it for speech sits inside a quotation or an echo of the Old Testament, and in each one the lips stand in for a person's words rather than for a piece of anatomy.

That substitution is what gives the word its edge. Lips are the outermost, most visible part of speaking, so they are the natural thing to name when a writer wants to hold what is heard apart from what lies behind it. Jesus quotes Isaiah to say that a people can honor God with their lips while their heart is far away (Matthew 15:8, Mark 7:6): the sound is right, the source is not. Romans 3:13 runs the same image the other direction, naming throat, tongue, and lips in turn as a body handed over to destructive speech.

The word keeps close company with two others. The tongue (γλῶσσα) is the moving organ inside the mouth, and it also came to mean a whole language; the mouth (στόμα) is the whole opening, and it is by far the commoner New Testament word for what someone says. Lips are the rim between the two, which is why a writer reaches for this word when the outward surface of speech is the point.

One use turns the picture around. Hebrews 13:15 calls praise "the fruit of lips that confess his name" and treats it as an offering carried to God, so the same part of the body that can betray a person is also what he brings to the altar.

Greek could speak of the lip of a cup, the lip of a pit, or the lip of the sea, much as English speaks of the mouth of a river or the foot of a hill. The body part supplies the picture, and the picture names an edge.

The New Testament has one instance of this, in Hebrews 11:12, where Abraham's descendants are as countless as "the sand which is by the seashore." The phrase is lifted from the promise God made to Abraham in Genesis 22:17, and the Greek behind "seashore" is literally the sea's lip, the line where the water stops and the land begins. English translations sensibly use the ordinary coastal word and let the image go.

That image is not an exotic flourish. It is a straight loan from the Hebrew of the Old Testament, where the word for lip (שָׂפָה) does the same double duty for a mouth's rim and a land's edge. Greek had its own dedicated word for a beach as a place to land a boat (αἰγιαλός); this word is the plainer choice, naming the coast simply as the sea's edge.