Etymology
Borrowed from Latin Mausōlēum, from Ancient Greek Μαυσωλεῖον (Mausōleîon), from Μαύσωλος (Maúsōlos, “Mausolus”) + -εῖον (-eîon, noun-forming suffix meaning “place or building associated with a specific purpose or person”). By surface analysis, Mausolus + -eum.
Definitions & examples from Wiktionary (CC BY-SA 3.0).