endometrioma
noun
en·do·me·tri·o·ma
| \ -ˌmē-trē-ˈō-mə
\
\
plural endometriomas
also endometriomata\ -mət-ə
\
\
Medical Definition of endometrioma
1
: a tumor containing endometrial tissue
2
: endometriosis
—used chiefly of isolated foci of endometrium outside the uterus