Michaelmas
Concise Oxford English Dictionary © 2008 Oxford University Press:
Michaelmas /ˈmɪk(ə)lməs/
▶noun the feast of St Michael, 29 September.
– origin OE Sanct Michaeles mæsse ‘Saint Michael's Mass’, referring to the Archangel.
'Michaelmas' also found in these Oxford entries:

