jeopardy (n.) Look up jeopardy at
late 14c., jupartie , ioparde, etc., "danger, risk;" earlier "a cunning plan, a stratagem" (c. 1300), from or based on Old French jeu parti "a lost game," more correctly "a divided game, game with even chances" (hence "uncertainty"). The sense perhaps developed in Anglo-French.

This is from jeu "a game" (from Latin iocus "jest;" see joke (n.)) + parti, past participle of partir "to divide" (see part (v.)). Jeopardous "in peril" (mid-15c.) is now obsolete.