Is “Capstan” a Scrabble word?
Yes
CAPSTAN
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 Capstan
/ˈkap.stən/
noun
1.A vertical cylindrical machine that revolves on a spindle, used to apply force to ropes, cables, etc. It is typically surmounted by a drumhead with sockets for levers used to turn it.
2.A rotating spindle used to move recording tape through the mechanism of a tape recorder.