n. An enemy; a foe.n. Specifically, the enemy of mankind; Satan; the devil.n. Hence, in a general sense, a devil; a demon; a malignant or diabolical being; an evil spirit.n. An exceedingly wicked, cruel, spiteful, or destructive person: as, a dynamite fiend; a fire fiend.n. A person who gives great annoyance; a persistent bore: as, the newspaper fiend; the hand-organ fiend.n. Synonyms See devil.