- Proto-Sino-Tibetan: *?
- Proto-Tibeto-Burman: *k/p/s-rwak (Matisoff, STEDT); *rwak (Benedict, 1972; LaPolla, 1987); *g-rwak (French, 1983)
A number of prefixes could be attached to this root, with each of the prefixes representing a contraction of another etymon. The *k- suffix was found in a number of other Lolo-Burmese (and rGyalrongic, per Prins 2011 and 2016) animal terms; the *s- prefix was a contraction of *sja‑n (“meat”); and the *p- suffix was a contraction of *bəw (“insect”).
- Written Tibetan: གྲོག་མ (grog ma, “ant”)
- possibly Situ: (kʰ)oroʔk
- *ruk (Sun, 1993)
- Anong: sərɔ