Answer: magnumopus

AnswerCrossword Clue
MAGNUMOPUSWriter's greatest work
MAGNUMOPUS"Great work"
MAGNUMOPUSMasterpiece
MAGNUMOPUSAuthor's chief work
MAGNUMOPUS"The Divine Comedy," for Dante
MAGNUMOPUSPrime piece
MAGNUMOPUSA GREAT WORK
MAGNUMOPUSMasterwork