Merriam-Webster Collegiate Dictionary - defile

 I. transitive verb  (~d; defiling)  Etymology: Middle English, alteration (influenced by filen to ~, from Old English fy?lan) of defoilen to trample, ~, from Anglo-French defoiller, defuler, to trample, from de- + fuller, foller to trample, literally, to full — more at full  Date: 14th century to make unclean or impure: as  a. to corrupt the purity or perfection of ; debase the countryside ~d by billboards  b. to violate the chastity of ; deflower  c. to make physically unclean especially with something unpleasant or contaminating boots ~d with blood  d. to violate the sanctity of ; desecrate ~ a sanctuary  e. sully, dishonor  Synonyms: see contaminate  • ~ment noun  • ~r noun  II. noun  Etymology: French defile, from past participle of defiler  Date: 1685 a narrow passage or gorge  III. intransitive verb  (~d; defiling)  Etymology: French defiler, from de- de- + filer to move in a column — more at file  Date: 1705 to march off in a line