"unclean, impure" (a, negative, kathairo, "to purify"), is used (a) of "unclean" spirits, frequently in the Synoptists, not in John's gospel; in Acts 5:16; 8:7; Revelation 16:13; 18:2 (in the 2nd clause the birds are apparently figurative of destructive satanic agencies); (b) ceremonially, Acts 10:14,28; 11:8; 1 Corinthians 7:14; (c) morally, 2 Corinthians 6:17 , including (b), RV; "no unclean thing;" Ephesians 5:5; Revelation 17:4 , RV, "the unclean things" (AV follows the text which have the noun akathartes, "the filthiness").
"common," is translated "unclean" in Romans 14:14 (thrice); in Revelation 21:27 , RV (AV, "that defileth," follows the inferior texts which have the verb koinoo: see B). See COMMON , DEFILE , C, UNHOLY , No. 2.
to make koinos, "to defile," is translated "unclean" in Hebrews 9:13 , AV, where the perfect participle, Passive, is used with the article, hence the RV, "them that have been defiled." See DEFILE , A, No. 1.
akin to A, No. 1, denotes "uncleanness," (a) physical, Matthew 23:27 (instances in the papyri speak of tenants keeping houses in good condition); (b) moral, Romans 1:24; 6:19; 2 Corinthians 12:21; Galatians 5:19; Ephesians 4:19; 5:3; Colossians 3:5; 1 Thessalonians 2:3 (suggestive of the fact that sensuality and evil doctrine are frequently associated); 4:7.
Note: In 2 Peter 2:10 , AV, miasmos, "a defilement," is rendered "uncleanness;" see DEFILEMENT , B, No. 2.