Usage: 8 forms in 14 verses
Form Translated As     In Verse(s)
κούφόν light LXX.1Sam.18.23
κούφοσ nimble LXX.Jer.46.6
was light LXX.2Sam.2.18
κούφον light LXX.2Kgs.20.10
κούφοισ light LXX.Eccl.9.11 • LXX.Isa.30.16
κούφοι Nimble LXX.2Sam.1.23 • LXX.Isa.30.16 • LXX.Lam.4.19
light LXX.1Chr.12.8
of light LXX.Isa.18.2
κούφησ a nimble LXX.Isa.19.1
κούφη it a light LXX.2Kgs.3.18
κουφότεροι Lighter than LXX.Jer.4.13

Liddell-Scott-Jones

κοῦφος (kouphos) light (in weight) G:A--C

κοῦφος, η, ον,

light, nimble, [Refs 8th c.BC+] adverb, κοῦφα ποσὶ προβιβάς stepping lightly on, [LXX+8th c.BC+] too buoyant, [Refs 5th c.BC+]

__2 metaphorically, easy, light, τελεῖν.. κούφαν κτίσιν to make achievement easy,[Refs 4th c.BC+]; κ. νύξ an easier night, of a sick person, [Refs 4th c.AD+]; περίπατος [Refs 1st c.BC+]; of government, light, κουφοτέραν βασιλείαν less oppressive, [Refs 5th c.BC+]; of an antagonist, easy-going, κουφότατος ἦν κρατήσας [Refs 4th c.BC+]
__3 unsubstantial, airy, vain, τὸ νέον.. κούφας ἀφροσύνας φέρον [Refs 5th c.BC+]; κ. πρᾶγμα a trifle, [Refs]; κ. γράμματα a small letter, [Refs 5th c.BC+]; of persons, ={κουφόνους}, [Refs 2nd c.AD+]; τὸ κοῦφον τοῦ νοῦ levity, [Refs 2nd c.AD+]
__4 light in point of weight, opposed to βαρύς, [Refs 5th c.BC+], etc.; κούφα σοι χθὼν ἐπάνωθε πέσοι may earth lie lightly on thee, [Refs 5th c.BC+]; κ. πνεύματα light airs, [Refs 5th c.BC+]
__4.b in Medicine texts in various uses, σικύαι κοῦφαι dry cuppings, [Refs 2nd c.AD+]; also κούφου μένοντος τοῦ ἰοῦ on the surface, [Refs 3rd c.AD+]; μὴν κ. the eighth month of pregnancy, [Refs 2nd c.AD+]; of food, easy to digest, light, [Refs 4th c.BC+]
__4.c of troops, light-armed, οἱ κ. τῶν στρατιωτῶν [Refs 5th c.BC+]
__4.d of ships, lightly-laden, [Refs 5th c.BC+]
__5 light, slight, ἁμαρτήματα [Refs 5th c.BC+]; κουφότερα γυμνάσια, opposed to ἀναγκαῖα, [Refs 4th c.BC+]
__6 empty, κεράμια [Refs 4th c.BC+] substantive, κοῦφον (i.e. κεράμιον), τό, jar, in plural, [Refs 3rd c.AD+]
__7 active, relieving, assisting, χερὶ κούφᾳ [Refs 5th c.BC+]: probably to be taken in this sense in [Refs 3rd c.BC+]
__II adverb -φως lightly, nimbly, κ. ὀροῦσαι [Refs 4th c.BC+]; κ. ἐσκευασμένοι, of soldiers, [Refs 5th c.BC+]; κ. ἔχειν to be relieved, [Refs 4th c.BC+]
__II.2 metaphorically, lightly, with light heart, κουφότερον μετεφώνεε [Refs 8th c.BC+]; κ. φέρειν, opposed to δεινῶς φ., [Refs 5th c.BC+]; διάγουσα κούφως doing well, of a patient, [Refs 5th c.BC+]
__II.3 lightly, with ease, [Refs 4th c.BC+]

LSJ Scripture Refs: LXX.Eccl.9.11