Is “Portamento” a Scrabble word?
Yes
PORTAMENTO
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 Portamento
/pɔːtəˈmɛntəʊ/
noun
1.A smooth, gliding transition from one note to another; used especially with stringed instruments, and sometimes on brass.