(n)North American perennial herb having small autumn-blooming purple or pink or white flowers; widely naturalized in Europe, Syn.New York aster, Aster novi-belgii
n. [ Michael + mass religious service; OE. Mighelmesse. ] The feast of the archangel Michael, a church festival, celebrated on the 29th of September. Hence, colloquially, autumn. [ 1913 Webster ]
Michaelmas daisy. (Bot.) See under Daisy. [ 1913 Webster ]