囚

Outer enclosure 囗 - the big square that wraps around the inside, formed by strokes 1, 2, and the closing stroke 5. The indexing radical, depicting a walled cell. Distinct from the smaller 口 (mouth) it visually resembles. Same wrapper family: 困 (trapped), 国 (country), 园 (garden) - all spaces with a definite boundary.

Inside 人 - a person, drawn as the side view of a walking figure. The whole character is a pure compound ideograph: a person locked inside four walls equals 'prisoner'. One of the most transparent characters in the script. Same person pictograph appears in 囚's relatives 因 (because - person on a mat) and 困 (trapped - tree in enclosure).