Is “Muggins” a Scrabble word?
Yes
MUGGINS
Valid in at least one Scrabble dictionary
Valid in these dictionaries
SOWPODS / CSW
Scrabble UK & International
TWL / NWL
Scrabble North America
Large English Dictionary
General English word list
Meaning of Muggins
/ˈmʌ.ɡɪnz/
noun
1.A fool or idiot (especially as an ironic way of referring to oneself).
“I suppose muggins here will have to do all the work, as usual.”
2.The act of stealing another player's points because they either mis-pegged or counted up incorrectly.
3.A game of dominoes in which the object is to make the sum of the two ends of the line some multiple of five.