flanker

flanker is a   Noun

Definition:

[1] One who, or that which, flanks, as a skirmisher or a body of troops sent out upon the flanks of an army toguard a line of march, or a fort projecting so as to command the side of an assailing body. They threw out flankers, and endeavored to dislodge their assailants. W. Irwing.

Synonyms: