止 was originally the shape of a human foot — toes and sole drawn as a picture. A foot is a step, and the place where a step halts is where the foot rests, so it came to mean "stop, cease." That is why 止 lives on inside countless characters as the "foot / step" component.

Look for 止 and you find footprints: 步 (bù, to walk) is two feet, 正 (zhèng, correct) is a foot heading for a goal, and 走 (run), 歷 (to pass through), 武 (martial — "to stop the spear"), 企 (to plan — standing on tiptoe) all grow from 止.

Mandarin: zhǐ, 3rd tone. 停止 (tíngzhǐ, to stop), 禁止 (jìnzhǐ, to prohibit), 不止 (bùzhǐ, more than / not limited to), 为止 (wéizhǐ, up until).

Japanese: on-reading シ (shi), kun と.まる (tomaru) and と.める (tomeru). 止まる (tomaru, to stop), 中止 (chūshi, cancellation), 禁止 (kinshi, prohibition), 行き止まり (ikidomari, dead end).

Korean hanja-sound "ji": 停止 (jeongji, suspension), 禁止 (geumji, prohibition), 防止 (bangji, prevention), 止血 (jihyeol, to stanch bleeding).

Memory aid: a single foot planted on the ground — where the step ceases is "stop."