From Wiktionary, the free dictionary
From omu- (class 3) + -nwa (“mouth”).
omunwa class 3 (plural eminwa class 4, augmentless munwa, plural augmentless minwa)
- lip
- Kaji, Shigeki (2007) A Rutooro Vocabulary[1], Tokyo: Research Institute for Languages and Cultures of Asia and Africa (ILCAA), →ISBN, page 6