late 16th century—from early modern Dutch ‘maelstrom’ (now ‘maalstroom’)—originally a proper name designating a powerful whirlpool in the Arctic Ocean, off the west coast of Norway, which was formerly supposed to suck in and destroy all vessels within a wide radius
1763 in French, 1798 in English—from the name of Étienne de Silhouette (1709-67), Controller-General of Finances in 1759—perhaps because he might have invented the portrait in profile obtained by tracing the outline of a head or figure by means of its shadow
After Ambrose Burnside, Union general in the U.S. Civil War, ‘burnsides’ (1866) denotes thick side whiskers worn with a moustache and clean-shaven chin; on the pattern of ‘side whiskers’, it was altered to ‘sideburns’ (1875), itself altered to ‘sideboards’ (1882).
The noun ‘wolf whistle’ appeared in the USA in 1943—Wolf-whistling was popularised by the wolf, a cartoon character created by Tex Avery in Little Red Walking Hood (1937), which reappeared in Red Hot Riding Hood (1943).
Classical Latin ‘muscŭlus’, literally ‘a little mouse’, also denoted ‘a muscle of the body’, especially of the upper arm, from the resemblance of a flexing muscle to the movements made by a mouse; ‘muscŭlus’ was also used in the sense of ‘mussel’.
First recorded in The Leeds Mercury (Leeds, Yorkshire) of Friday 26 August 1938, the phrase ‘to use one’s loaf’ means ‘to use one’s common sense’. Here, ‘loaf’, a shortening of ‘loaf of bread’, is rhyming slang for ‘head’.
‘handbag’: to bully or coerce by subjecting to a forthright verbal assault or criticism—originally used with reference to British Prime Minister Margaret Thatcher in The Economist (7 August 1982)—from literal meaning ‘to batter or assault with a handbag’
Of American-English origin, the colloquial phrase ‘hot under (or ‘in’) the collar’ means ‘extremely exasperated or angry’. The earliest instance that I have found is from The Chicago Tribune (Chicago, Illinois) of 8th July 1869.
U.S., 1876—‘bulldozers’: members or supporters of the Democratic Party who used threats and acts of violence in order to prevent Afro-Americans from voting for Republican candidates
Italian translation of Latin ‘in pectore’ (‘in the breast’, ‘in the secret of the heart’)—when a pope announces that he has appointed a cardinal whom he reserves ‘in petto’, it means that he will reveal this cardinal’s name later