横
héng , hèng · HSK 6
across
➖ Wood + yellow = héng: a yellow wooden beam laid across horizontally
The character combines 木 (wood) and 黄 (yellow). A beam is a horizontal timber — yellow like fresh-cut lumber. The alternate reading hèng means perverse, as if something cuts across your path.
横 — wood radical 木 + 黄 (huáng, phonetic)
A semantic-phonetic compound: 木 'wood' gives the meaning (a horizontal wooden bar across a gate), while 黄 supplies the sound. It originally meant the crossbar of a gate, then extended to 'horizontal' generally. The reading hèng later developed the sense of 'unruly' or 'unexpected'.