ˈməgə̇nz noun
( plural muggins )
Usage: often capitalized
Etymology: probably from the name Muggins
1.
a. : 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
2. : simpleton
had seen too many muggins come bowing and smiling — Enid Bagnold