Common body-part compounds: 脚趾 (toes), 脚踝 (ankle), 脚跟 (heel), 脚步 (footstep), 脚印 (footprint). Measure with 只 for one foot or 双 for a pair.
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An archaic reading 脚 survives only in 脚色 (theatrical role), a variant of the far more common 角色. Modern writing almost always uses 角色; treat 脚 as jiǎo everywhere else.
Right phonetic 却 supplies the sound (què → jiǎo, with initial drift; the link is tighter to the older reading 脚). 却 itself shows 去 'go' beside 卩 'kneeling figure' - a person stepping back, a happy semantic echo of feet in motion.
