the first day of May, long celebrated with various festivities, as the crowning of the May queen, dancing around the Maypole, and, in recent years, often marked by labor parades and political demonstrations.
"first of May," mid-15c.. Accounts of merrymaking on this date are attested from mid-13c. Synonymous with "communist procession" from at least 1906. The May Queen seems to be a Victorian re-invented tradition.
"distress call," 1927, from Fr. m'aider, shortening of venez m'aider "come help me!"