Unclean
来自Big Physics
wiktionary
From Middle English unclene, from Old English unclǣne, equivalent to un- + clean.
etymonline
unclean (adj.)
Old English unclæne, "morally impure, defiled, unfit for food," from un- (1) "not" + clean (adj.). Literal sense of "dirty" is recorded from mid-13c.
