One who pertinaciously contends for some trifling things, as a point of etiquette; an unreasonable, obstinate contender; as, a stickler for ceremony.

One who arbitrates a duel; a sidesman to a fencer; a second; an umpire.

someone who insists on something; "a stickler for promptness"

Unusual facial features, eye problems, arthritis

One who stickles.