別腹

Compound of 別(べつ) (betsu, “separate”) + 腹(はら) (hara, “stomach, belly”). The hara changes to bara as an instance of rendaku (連(れん)濁(だく)).

• (Tokyo) べつばら [bètsúbárá] (Heiban – [0])^[1]
• IPA^(key): [be̞t͡sɨba̠ɾa̠]

別(べつ)腹(ばら) • (betsubara) 

1. “separate stomach”, appetite or ability to continue eating after a meal, a hollow leg

   甘(あま)い物(もの)は別腹(べつばら)だ。

   Amai mono wa betsubara da.

   I've got a separate stomach (hollow leg) for sweets.

2. “separate belly” siblings, half siblings who share the same father but have different mothers

• (hollow leg): This sense often extends to the appetite for or capacity to eat a particular type of food, such as sweets.

From Middle Chinese compound 別腹 (bhyɛt biuk, literally “separate, other + belly, abdomen”). Attested in Japanese from the 15th century.^[2]

• IPA^(key): [be̞p̚pɯ̟kɯ̟]

別(べっ)腹(ぷく) • (beppuku) 

1. “separate belly” siblings, half siblings who share the same father but have different mothers

   Synonyms: 異腹 (ifuku), 腹違い (harachigai)

• Shōgaku Tosho (1988), 国語大辞典（新装版） [Unabridged Dictionary of Japanese (Revised Edition)] (in Japanese), Tōkyō: Shogakukan, →ISBN