Is “Sesquialtera” a Scrabble word?
Yes
SESQUIALTERA
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 Sesquialtera
noun
1.A ratio of 3:2.
2.An organ stop that uses two ranks of different pipes.