From katharos; to cleanse (literally or figuratively) -- (make) clean(-se), purge, purify.
see GREEK katharos
1. to make clean, to cleanse;
a. from physical stains and dirt: e. g. utensils, Matthew 23:25 (figuratively, Matthew 23:26); Luke 11:39; food, Mark 7:19; τινα, a leper, to cleanse by curing, Matthew 8:2; Matthew 10:8; Matthew 11:5; Mark 1:40-42; Luke 4:27; Luke 5:12; Luke 7:22; Luke 17:14, 17 (Leviticus 14:8); to remove by cleansing: ἡ λέπρα ἐκαθαρίσθη, Matthew 8:3 (καθαριεῖς τό αἷμα τό ἀναίτιον ἐξ Ἰσραήλ, Deuteronomy 19:13; ἐκαθαριζε τήν περί ταῦτα συνήθειαν, the custom of marrying heathen women, Josephus, Antiquities 11, 5, 4; καθαιρεῖν αἷμα, Homer, Iliad 16, 667; cf. ἐκκαθαίρω).
b. in a moral sense; α. to free from the defilement of sin and from faults; to purify from wickedness: ἑαυτόν ἀπό μολυσμοῦ σαρκός, 2 Corinthians 7:1; τῇ πίστει τάς καρδίας, Acts 15:9 (καρδίαν ἀπό ἁμαρτίας, Sir. 38:10); τάς χεῖρας, to abstain in future from wrong-doing, James 4:8. β. to free from the guilt of sin, to purify: τινα ἀπό πάσης ἁμαρτίας, 1 John 1:7; (τινα ἀπό πάσης ἀδικίας, 1 John 1:9); τήν συνείδησιν ἀπό νεκρῶν ἔργων, Hebrews 9:14; τήν ἐκκλησίαν τῷ λουτρῷ τοῦ ὕδατος (instrumental dative), Ephesians 5:26; λαόν ἑαυτῷ, Titus 2:14. γ. to consecrate by cleansing or purifying: τί ἐν τίνι, dative of instrumentality (Winer's Grammar, 388 (363)), Hebrews 9:22; equivalent to to consecrate, dedicate, τί τίνι (dative of instrumentality), ibid. 23.
2. to pronounce clean in a levitical sense: Acts 10:15; Acts 11:9 (Leviticus 13:13, 17, 23, 28). (Compare: διακαθαρίζω.)