dud

(noun) someone who is unsuccessful. Synonyms: flop, washout.

(noun) an explosion that fails to occur. Synonyms: misfire.

(noun) an event that fails badly or is totally ineffectual. Synonyms: turkey, bomb. Examples: "The first experiment was a real turkey." "The meeting was a dud as far as new business was concerned."

(adj) failing to detonate; especially not charged with an active explosive. Example: "He stepped on a dud mine."