Quick Definition
I cleanse, purify, prune
Strong's Definition
to cleanse, i.e. (specially) to prune; figuratively, to expiate
Derivation: from G2513 (καθαρός);
KJV Usage: purge
Thayer's Greek Lexicon
καθαίρω; perfect passive participle κεκαθαρμενος; (καθαρός); to cleanse, properly, from filth, impurity, etc.; trees and vines (from useless shoots), to prune, Joh_15:2 (δένδρα ... ὑποτεμνομενα καθαίρεται, Philo de agric. § 2 (cf. de somniis ii. § 9 middle)); metaphorically, from guilt, to expiate: passive Heb_10:2 R G (see καθαρίζω, at the beginning) (Jer_13:27; and so in Greek writings from Herodotus down). (Compare: διακαθαίρω, ἐκκαθαίρω.)
Mounce Concise Greek Dictionary
καθαίρω kathairō 1x
to cleanse from filth; to clear by pruning, prune, Joh_15:2 ;
met. to cleanse from sin, make expiation
Abbott-Smith Greek Lexicon
καθαίρω
( < καθαρός ),
[in LXX : Isa_28:27 ( H1758 ho .), 2Sa_4:6 , Jer_51:39 ΰ * ;]
to cleanse: of pruning, Joh_15:2 ( cf. καθαρίζω ).†
Moulton & Milligan — Vocabulary of the Greek NT
καθαίρω [page 310]
With the use of this verb in Joh_15:2 we may compare P Lille I. 5 .24 (B.C. 260 59) ἐκ τοῦ ἰδίου ξυλοκοπήσει καὶ τὴγ γῆν καθαρεῖ . Cf. P Tebt II. 373 .10 (A.D. 110 1) ἐφ᾽ ᾧ ὁ Ἥρων μετρήσι καὶ καθαρεῖ καθ᾽ ἔτος εἰς τὸ δημόσιον . . . [τ ]ὰ . . . ἐκφόρια , on condition that Heron shall measure out and winnow the produce (cf. 2Ki_4:6 ) annually for the State. The verb is common in the inscrr, of ceremonial cleansing, e.g. Michel 694 .68 (B.C. 91) ἔστι δὲ ἃ δεῖ παρέχειν πρὸ τοῦ ἄρχεσθαι τῶν μυστηρίων· ἄρνας δύο λευκούς , . . . καὶ ὅταν ἐν τῶι θεάτρωι καθαίρει , χοιρίσκους τρεῖς : cf. Kaibel 104 .1 f.
Ἐνθάδε Διάλογος καθαρῶι πυρὶ γυῖα καθήρας
ἀσκητὴς σοφίης ὤιχετ᾽ ἐς ἀθανάτους .
The compound ἀνακαθαίρω is found in P Lond 1177 .332 (A.D. 113) (= III. p. 190).
Liddell-Scott — Intermediate Greek Lexicon
καθαίρω [Etym: καθαρός] of the person or thing purified, "to make pure or clean, cleanse, clean, purge", καθήραντες χρόα ὕδατι Od. :— "to purge, clear" a land of monsters and robbers, Soph. in religious sense, "to cleanse, purify", [δέπας] ἐκάθηρε θεείωι "purified" it by fumigating with sulphur, Il. ; καθ. τινὰ φόνου "to purify" him "from" blood, Hdt. ; Δῆλον κ. id=Hdt. :—Mid. "to purify oneself, get purified", id=Hdt. ; οἱ φιλοσοφίαι καθηράμενοι Plat. :—so Pass., κεκαθαρμένος id=Hdt. "to prune" a tree, i. e. "clear" it of superfluous wood, NTest. metaph., = μαστιγόω, like our vulgar phrase ""to rub down", " Theocr. of the thing removed by purification, "to purge away, wash off or away", λύματα Il. ; ῥύπα Od. ; φόνον Aesch. c. dupl. acc., αἷμα κάθηρον Σαρπηδόνα "cleanse" Sarpedon "of" blood, "wash" the blood "off" him, Il. :—Pass., φόνον καθαρθείς Hdt.
STEPBible — Tyndale Abridged Greek Lexicon
καθαίρω
(καθαρός), [in LXX: Isa.28:27 (דּוּשׁ ho.), 2Ki.4:6, Jer.51:39 א* ;]
to cleanse: of pruning, Jhn.15:2 (cf. καθαρίζω).†
(AS)