The character 足 (zú): foot

A broad staircase of pale stone climbs a green misty Chinese mountain toward a small red pavilion, between pines and rocks under a golden sun. Terracotta orange prints of bare feet march up the left half of the steps toward the pavilion. At the right, on the steps, the character 足 in deep brown: an empty rectangle above, and below it a short stem, a small stroke at its right, a slant falling to the lower left and a long stroke flattening away to the right.

Pronunciation: zú
Strokes: 7
Radical: 足
Made of: 口止

What it means

(bound form) foot; leg; sufficient; ample; as much as; fully

Where its shape comes from

Xu Shen names the two elements he sees, 止, a footprint, and 口, and adds the remark "it is below". The upper part has stopped being read as a mouth: palaeographers take it for the knee or the calf, the leg that sits above the foot, and it has only been a square since regularisation. About the lower part there is no argument at all. It really is a footprint, the very one you meet again in 步 bù and in 正 zhèng.

Source: Xu Shen, Shuowen Jiezi (121 CE); the Chinese University of Hong Kong character database.

A way to remember it

The square of 口, learned at the very start of the course, and under it a foot spreading out: a short vertical, a small stroke to its right, then two slants, one going off to the left and one to the right as it flattens. The last of them is the longest line in the character.

This is a memory aid, not the origin of the character.

Words it appears in

满足 mǎn zú · HSK 5 to satisfy; to meet (the needs of); satisfied; content
不足 bù zú · HSK 5 insufficient; lacking; deficiency; not enough; inadequate; not worth; cannot; should not
足以 zú yǐ · HSK 6 sufficient to...; so much so that; so that
十足 shí zú · HSK 6 ample; complete; hundred percent; a pure shade (of some color)
充足 chōng zú · HSK 6 adequate; sufficient; abundant
立足 lì zú · HSK 6 to stand; to have a footing; to be established; to base oneself on

Writing it

See the stroke order of 足, animated stroke by stroke.