defile

Defile is a verb with several related senses. In moral or hygienic usage, it means to make something dirty or impure, to contaminate or desecrate, often with religious or ceremonial implications. It can also describe sullying a reputation, memory, or sacred place. In military or marching contexts, defile can mean to move troops or people in a single file or through a narrow passage, so that they pass by one after another. The phrase is commonly used as “defile through” or “defile past.”

As a noun, defile denotes a narrow pass or gorge, especially in mountainous terrain, through which people or armies move. This geographic sense is common in travel writing, historical accounts, and descriptions of terrain. The two main senses are distinct but share the underlying idea of moving along a line or through a constricted space, whether physically or metaphorically.

Etymology and usage notes: the word derives from Old French defiler, meaning to glide or move in a line, with its English senses expanded to include both pollution and orderly movement. In modern English, the moral sense is frequently found in religious, legal, or formal contexts, while the geographic and military senses appear in descriptions of terrain, operations, and marching formations. Defilement is the related noun for the act of polluting or desecration, and defiling is the present participle form.