c. 1300, "observance of ceremony," from Old French solemnite, solempnete "celebration, high festival, church ceremony" and directly from Latin solemnitatem (nominative solemnitas) "a solemnity," from sollemnis (see solemn). Meaning "state of being solemn" is from 1712. Related: Solemnities.[solemnity etymology, solemnity origin, 英语词源]