Answer: silentcal

AnswerCrossword Clue
SILENTCALNickname for President Coolidge, from his natural demeanor
SILENTCALNickname for Coolidge
SILENTCAL'20s White House nickname
SILENTCAL.30's nickname
SILENTCALPresidential nickname
SILENTCALNickname of the 30th president
SILENTCAL30th president, informally