From Wiktionary, the free dictionary
From 小 (ko-) + 腹 (hara). The hara changes to bara as an instance of rendaku (連濁).
こばら • (kobara) ←こばら (kobara)?
- stomach (as the subject of a minor action)
- 小腹がすいた
- kobara ga suita
- a little hungry (as opposed to 腹がすいた)