Is “Supermajority” a Scrabble word?
Yes
SUPERMAJORITY
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 Supermajority
/ˌs(j)upɜɹməˈd͡ʒɔɹɪti/
noun
1.Any qualified majority, specified in advance of a vote, required for the vote to be passed