Several parts combine into one character.

Compound character: 步 (footsteps / walking) + 戌 (an axe / Year-of-the-Dog signal). The encoded meaning: "the steps of a year, marked with an axe-cut" — the agricultural cycle ending in harvest and sacrificial offering. Where 年 is the ordinary year-cycle (from earlier batches), 歲 carries weightier ceremonial connotation: ages, eras, dignified time. Three forms: 繁體 歲 / 新字体 歳 / 简体 岁 (the most diverged simplification — Chinese radically reduced the strokes).

The primary modern usage is for COUNTING AGE in years — and this is one of the most everyday CJK vocabulary items.

Mandarin: suì, falling 4th tone (simplified 岁). 几岁? (Jǐ suì? "How old?" — used for children) is among the first questions a Mandarin learner masters. 二十岁 (èrshí suì, 20 years old), 岁数 (suìshu, age — neutral final tone), 万岁 (wànsuì, "ten thousand years!" — the famous cheer for emperors and political leaders). Note that for adults, more polite forms like 年纪 / 年龄 are sometimes preferred, but 岁 remains universal.

Japanese: on-reading サイ (sai) — 二十歳 (irregular kun-reading hatachi — "20 years old", THE coming-of-age milestone in Japan, celebrated as 成人式), 歳末 (saimatsu, year-end — every Japanese department store does 歳末 sales), 万歳 (banzai, "Long live!" cheer — this is the same character but pronounced differently from 万歳 in older Buddhist contexts). Kun-reading とし (toshi) — same kun-reading as 年 (year, batch K.6), the two characters share much vocabulary. お歳暮 (oseibo, year-end gift — a major Japanese gift-giving season).

The Japanese 二十歳 (hatachi) — turning 20 — is a culturally weighty milestone with formal ceremonies, kimono dressing, and government recognition. Mastering this character is essential for navigating Japanese age etiquette.

Memory aid: a year measured by footsteps + axe — the cyclical agricultural year, weighted with ceremony.