Loser

wiktionary

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From Middle English loser, losere, equivalent to lose +‎ -er. In the sense of contemptible or worthless individual, perhaps an alteration of losel, which see.

etymonline

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loser (n.)

mid-14c., "a destroyer" (a sense now obsolete), agent noun from lose (v.). Sense of "one who suffers loss" is from 1540s; meaning "horse that loses a race" is from 1902; "convicted criminal" is from 1912; "hapless person, one who habitually fails to win" is by 1955 in U.S. student slang. Bad loser (also poor, sore, etc.) "one who takes defeat with bad grace" is by 1892.