to make foul, dirty, or unclean; pollute; taint; debase.
2.
to violate the chastity of.
3.
to make impure for ceremonial use; desecrate.
4.
to sully, as a person's reputation.
Origin: 1275–1325; Middle English defilen, defelen, alteration of defoilen (by association with filen to file3) < Anglo-French, Old French defouler to trample on, violate; compare Old English befȳlan to befoul
an extraordinary or unusual thing, person, or event; an exceptional example or instance.
a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.
a children's mummer's parade, as on the Fourth of July, with prizes for the best costumes.
to tarnish or sully the brightness of; taint; corrupt
3.
to damage or sully (someone's good name, reputation, etc)
4.
to make unfit for ceremonial use; desecrate
5.
to violate the chastity of
[C14: from earlier defoilen (influenced by filen to file³), from Old French defouler to trample underfoot, abuse, from de- + fouler to tread upon; see full²]