Birthday
来自Big Physics
wiktionary
From Middle English birthdai, birtheday, from Old English ġebyrddæġ(“birthday”), equivalent to birth + day. Compare Saterland Frisian Gebuursdai(“birthday”), Dutch geboortedag(“birthday”), Low German Geboortsdag(“birthday”), German Geburtstag(“birthday”), Norwegian bursdag, gebursdag(“birthday”).
Eclipsed non-native Middle English nativitee(“birth, nativity, birthday”), from Old French nativité, nativited, from Latin nātīvitas.
etymonline
birthday (n.)
late 14c., from Old English byrddæg, "anniversary or celebration of one's birth" (at first usually a king or saint); see birth (n.) + day. Meaning "day on which one is born" is from 1570s. Birthnight is attested from 1620s.
