USA, 1992—to make or repair (something) in an improvised or inventive way, making use of whatever items are at hand—also used figuratively—refers to Angus MacGyver, the lead character in the U.S. television series MacGyver (1985-92)
Australia, 1946—to return to one’s profession after retirement; of a singer or other performer: to make frequent comebacks—from the repeated farewell performances given by Australian opera singer Dame Nellie Melba
personifies the highest degree of disability or incompetence—Sydney, Australia, 1910s—variant, probably referring to a local individual, of the earlier synonymous phrase ‘blind man’
UK, 1943—a medal awarded to an animal in recognition of an act of bravery—named after M. E. Dickin, founder of the People’s Dispensary for Sick Animals in 1917
US 1960—person of whom only one aspect is known; continual phenomenon—from the one-sided continuous surface formed by joining the ends of a half-twisted strip
USA, 1990s—purveyor of doom, especially agent of death, force of suicide—refers to Jack Kevorkian (1928-2011), U.S. physician and advocate of assisted suicide
1934—pompous, reactionary type of person—from the cartoon character (a pompous retired British army officer voicing a hatred of new ideas) created by David Low