1: καινός
(Strong's #2537 — Adjective — kainos — kahee-nos' )

denotes "new," of that which is unaccustomed or unused, not "new" in time, recent, but "new" as to form or quality, of different nature from what is contrasted as old. "'The new tongues,' kainos, of Mark 16:17 are the 'other tongues,' heteros, of Acts 2:4 . These languages, however, were 'new' and 'different,' not in the sense that they had never been heard before, or that they were new to the hearers, for it is plain from Acts 2:8 that this is not the case; they were new languages to the speakers, different from those in which they were accustomed to speak.

Matthew 26:28 John 13:34Galatians 6:152—Corinthians 5:17Ephesians 4:24Ephesians 2:15Revelation 2:17Revelation 3:12Revelation 5:9Revelation 21:1Revelation 3:1221:2Revelation 21:5Matthew 9:17Mark 2:22 Luke 5:38
2: νέος
(Strong's #3501 — Adjective — neos — neh'-os, neh-o'-ter-os )

signifies "new" in respect of time, that which is recent; it is used of the young, and so translated, especially the comparative degree "younger;" accordingly what is neos may be a reproduction of the old in quality or character. Neos and kainos are sometimes used of the same thing, but there is a difference, as already indicated. Thus the "new man" in Ephesians 2:15 (kainos) is "new" in differing in character; so in Ephesians 4:24 (see No. 1); but the "new man" in Colossians 3:10 (neos) stresses the fact of the believer's "new" experience, recently begun, and still proceeding. "The old man in him ... dates as far back as Adam; a new man has been born, who therefore is fitly so called" [i.e., neos], Trench, Syn. lx. The "New" Covenant in Hebrews 12:24 is "new" (neos) compared with the Mosaic, nearly fifteen hundred years before; it is "new" (kainos) compared with the Mosaic, which is old in character, ineffective, Hebrews 8:8,13; 9:15 .

Matthew 9:17Mark 2:22Luke 5:37-39Matthew 26:29Mark 14:251—Corinthians 5:7YOUNGYOUNGER.
3: στερεόω
(Strong's #4732 — Verb — prosphatos — ster-eh-o'-o )

originally signifying "freshly slain," acquired the general sense of "new," as applied to flowers, oil, misfortune, etc. It is used in Hebrews 10:20 of the "living way" which Christ "dedicated for us ... through the veil ... His flesh" (which stands for His expiatory death by the offering of His body, ver. 10). In the Sept., Numbers 6:3; Deuteronomy 32:17; Psalm 81:9; Ecclesiastes 1:9 . Cp. the adverb prosphatos "lately, recently," Acts 18:2 .

Matthew 9:16Mark 2:21UNDRESSED.