1880-85; named after the hero of Tam O'Shanter (1791), poem by Robert Burns
British Dictionary definitions for tam-o'-shanter
tam-o'-shanter
/ˌtæməˈʃæntə/
noun
1.
a Scottish brimless wool cap with a bobble in the centre, usually worn pulled down at one side Also called tam, tammy
Word Origin
C19: named after the hero of Burns' poem Tam o' Shanter (1790)
Word Origin and History for tam-o'-shanter
n.
c.1840, type of bonnet formerly worn by Scottish plowmen, from Tam O'Shanter "Tom of Shanter," name of hero in a poem of the same name by Robert Burns, written 1790. The woolen cap became fashionable for ladies c.1887.