Is “Cusp” a Scrabble word?
Yes
CUSP
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 Cusp
/kʌsp/
noun
1.A sharp point or pointed end.
2.An important moment when a decision is made that will determine future events.
3.A point of a curve where the curve is continuous but has no derivative, but such that it has a derivative at every nearby point.
Synonyms: ord
verb
1.To behave in a reckless or dangerous manner.