The story
- Latincrassus
- Vulgar Latin*crassia
- Anglo-Normangrece
- Middle Englishgrece
- Englishgrease
- English todaygreaseball
From grease + -ball.; possibly derived from the fact that Italians and Italian-Americans are stereotyped as having greasy or greased-up hair.
Etymology from Wiktionary, CC BY-SA 4.0.