Is “Joinder” a Scrabble word?
Yes
JOINDER
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 Joinder
noun
1.The joining of a litigant to a suit.
2.The act of joining; a putting together; conjunction.