腹
フク, はら
abdomen, belly, stomach
JLPT3 G6 S13 F1286
复 is an abbreviated form of 畐 as described in 副 (alcohol container with a bulging middle) + 夂 leg/foot pointed downward (→ action indicator) → send back/return something received (in kind) → double back. 腹 is as per 复# (double back) + 肉 flesh → *stomach* of an obese person (i.e. with an extra layer of fat doubled atop the abdominal muscles) → *abdomen*; *belly*.
[Full Kanji Etymology List]