vulgar
common or coarse
Root
- vulg / vulgar: common people, public, common property, or widely known
Other words with the vulg / vulgar root
- divulge: to reveal private information
Vulgar first points to common or public people before it can mean coarse.
The joke was vulgar enough to make the whole table go quiet.
Vulgar is useful because the older common/public sense explains divulge. A private fact becomes common knowledge; later vulgar can mean coarse or low.