闲

Outer indexing gate radical 门 — simplified from 門 (a pair of swinging doors). Anchors 闲 in the gate family alongside 间 (between), 问 (ask), 闭 (close), 闯 (rush in). 闲 originally depicted a horizontal bar (木 wood) placed across the gate — a barricade making it impossible to leave, hence "shut in, idle, leisure."

Inside 木 — pictograph of a tree, here functioning as a wooden barrier or door-bolt placed across the gateway. Together the components depict "wood-in-the-gate" — the household closed for the night, no business going on. From this concrete picture came the abstract sense of leisure, idleness, free time. A textbook 会意字.