成年
せいねん · seinen · JLPT N3 · noun
majority
🎂 成 become + 年 years = the years when you become an adult
成 means become or complete and 年 means year or age, so 成年 is the age you grow into. Don't confuse it with 青年, also read seinen, which means youth. Japan's age of majority has been 18 since 2022.
成 — 戊 (halberd/weapon) + 丁 (nail/man)
Originally a pictograph of a halberd or axe-like weapon, suggesting the act of completing a task by force. Over time it shifted from 'to subdue' to the broader meaning 'to accomplish' or 'to become'. The 丁 element inside also hints at the chéng sound.
年 — grain 禾 over person 人 (oracle bone)
Originally a pictograph of a person carrying a bundle of harvested grain on their back, representing the yearly grain harvest. Because harvests came once a year, the character shifted from meaning 'harvest' to meaning 'year.' The modern form 年 obscures the original 禾 (grain) + 人 (person) structure.