: a provision in many games played in England that if a player fails to record an earned score promptly his opponent may say muggins and claim that score—used especially in cribbage and dominoes
b
: a dominoes game identical with sniff except that the muggins provision is included
c
: any of various card games in which a score overlooked may be claimed by saying muggins or in which the player with the worst score is called muggins—used especially in children's games