Queen Mary
/ˌkwiːn ˈmɛːri/noun
A type of long low-loading road trailer originally used to transport tanks, aircraft, etc., during the Second World War (1939–45). Now chiefly historical.
Origin
1920s (in an earlier sense). From Queen Mary, the name of the wife of King George V, King of Great Britain and Ireland, who was Queen Consort from 1911–36.