Is “Thumbscrew” a Scrabble word?
Yes
THUMBSCREW
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 Thumbscrew
noun
1.A screw that can be turned with the thumb and fingers.
2.An instrument of torture used to crush the fingers.
3.A weakness that can be taken advantage of.
“Law 33: Discover Each Man's Thumbscrew ― Robert Greene, The 48 Laws of Power”
Synonyms: pilliwinks