late 14c., "one who or that which makes notches," agent noun from score (v.). By 1732 as "one who keeps record of a score" (in a match or game), by 1884 as "one who makes a score" in a match or game.
Entries linking to scorer
score v.
late 14c., "to record by means of notches;" c. 1400, "to cut with incisions or notches;" see score (n.). Meanings "to keep record of the scores in a game, etc." and "to succeed in making or adding a point for one's side in a game, etc." both are attested from 1742 (Hoyle on whist).
Meaning "to be scorekeeper, to keep the score in a game or contest" is from 1846. In the musical sense of "write out in score" by 1839. The slang sense "buy a narcotic drug" is by 1935; in reference to men, "achieve intercourse" by 1960. Related: Scored; scoring.