腰
ヨウ, こし, うすぐ

loins, hips, waist, low wainscoting

JLPT2 G7 S13 F1306

要# waist/hips + 肉 flesh → *waist*; *hips*; *small of the back*. 腰 was devised to replace 要 after the latter acquired its extended meanings.

[Full Kanji Etymology List]