Transferred use of the surname, in origin a local name from the very numerous places named with Old English þorn ‘thorn bush’ + tūn ‘enclosure, settlement’. The given name is associated with the American writer Thornton Wilder (1897–1975).
Scottish, English, and Irish: 1. from the Middle English, Old French personal name Michel, vernacular form of Michael. 2. nickname for a big man, from Middle English michel, mechel, muchel ‘big’. 3. Irish (County Connacht): surname adopted as equivalent of Mulvihill.