Answer: fieriest

AnswerCrossword Clue
FIERIESTMost impassioned
FIERIESTMost passionate
fieriestFIERY, intensely hot
fieriestConsisting of fire or burning strongly and brightly
fieriest(of a person) Having a passionate, quick-tempered nature
fieriest(of behavior or words) Passionately angry and deeply felt
fieriestHaving the bright color of fire