Several parts combine into one character.

後 in oracle bone form pictured a foot (夂) on a road (彳) trailing a small cord (幺) — "moving slowly because tied behind, falling behind". From there: "behind / after / later". Pairs with 前 in both spatial and temporal sense.

Critical script-form alert. This is one of the most confusing simplification cases in the entire CJK system: — Traditional 繁體: 後 (the original character meaning "behind / after"). — Japanese 新字体: 後 (kept the traditional form). — Simplified 简体: 后 — but here's the problem: 后 was already a separate, completely unrelated character meaning "queen / empress" (e.g., 皇后, the empress). Mainland Chinese simplification merged the two characters into a single form, so in 简体 the character 后 now does double duty. Context disambiguates, but learners must memorize that 后 simplified covers BOTH "behind" and "queen".

This is the kind of case English speakers most often miss. If you only learn simplified Chinese and try to read traditional or Japanese text, you will see 後 as a "new" character — but it is actually the ancestor of half the modern 后. Learn both forms to read across the script-form boundary.

Mandarin: hòu, falling 4th tone. 后面 (hòumiàn, behind), 以后 (yǐhòu, after — extremely high frequency), 然后 (ránhòu, then / afterwards), 最后 (zuìhòu, finally), 后悔 (hòuhuǐ, regret).

Japanese (using 後): on-readings ゴ (go) in 午後 (gogo, PM), 食後 (shokugo, after meals); コウ (kō) in 後悔 (kōkai, regret), 後援 (kōen, support / backing). Kun-readings split: のち (nochi, later — formal), あと (ato, after / behind — everyday), うしろ (ushiro, behind — spatial). Native speakers choose between あと and のち based on register, with あと far more common in casual speech.

Memory aid: a small foot dragging a cord on the road — the slow follower behind.

In Japan·後 = behind / after

In China·后 = behind / after (also: queen, in classical usage 王后)