PRISSIEST
Scrabble letter values: P3R1I1S1S1I1E1S1T1 = 11
Definition
PRISSIEST is the superlative of PRISSY.
adjective PRISSY: exaggeratedly proper.
Synonyms of PRISSY: priggish, prim, prudish, puritanical, square-toed, straitlaced, strait-laced, straightlaced