Masterwork and Monumental work

Masterwork noun - Something (as a work of art) that is a great achievement and often its creator's greatest achievement.

Monumental work and masterwork are semantically related In some cases you can use "Monumental work" instead a noun "Masterwork".

Masterwork and monumental work are semantically related in greatest single work topic. You can use "Masterwork" instead a noun phrase "Monumental work".