西暦
せいれき · seireki · JLPT N2 · noun
Christian Era
📅 西 west + 暦 calendar = the Western calendar's year count, dated as AD
西 means west and 暦 means calendar, so 西暦 is the Western calendar. It counts years in the Christian Era, the same system as AD (Anno Domini, Latin for in the year of the Lord).
西 — top 覀 (cover) + bottom 儿 (legs); originally a bird in nest
Originally a pictograph of a bird settling into its nest at dusk. Because birds return to roost when the sun sets in the west, the character was borrowed to mean 'west.' The original 'nest' meaning was later written with 棲/栖.