Is “Stiffest” a Scrabble word?
Yes
STIFFEST
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 Stiffest
adjective
1.(of an object) Rigid; hard to bend; inflexible.
2.(of policies and rules and their application and enforcement) Inflexible; rigid.
3.(of a person) Formal in behavior; unrelaxed.