1973—someone or something that polarises opinions by provoking either strongly positive or strongly negative reactions, rather than indifference—proprietary name for a savoury paste made from yeast and vegetable extract, which is either loved or hated
UK, 1894—a love-relationship in which one member of a married couple is involved with a third party—loan translation from French ‘triangle éternel’, coined by Alexandre Dumas fils in L’Homme-Femme (1872), a pamphlet about a wronged husband’s right to take the life of his adulterous wife
UK, 1856—a talisman associated with a woman—a woman likened to a talisman, especially a female sports player regarded as the leading representative of her team—alteration of ‘talisman’ with substitution of ‘woman’ for the element ‘‑man’
USA, 1888—an enigmatic, mysterious smile, reminiscent of that represented in the Mona Lisa, a portrait of Monna Lisa del Giocondo, painted by Leonardo da Vinci
1923: a small garment worn to cover the genitals—hence (1926): anything intended to conceal something regarded as shameful or indecent—from French ‘cache-sexe’, from ‘cacher’ (to hide) and ‘sexe’ (sex, genitals)
USA, 1924—a questionable or unorthodox practice that has long been established—from literal uses (19th century onwards) referring to former Spanish colonies in America
humorous variant of ‘one man’s meat is another man’s poison’—USA, 1929—refers to the phrase ‘the law of the Medes and Persians’, denoting something which cannot be altered
also ‘to throw a wobbler’—New Zealand, 1964—to lose one’s self-control in a fit of nerves, temper, panic, etc.—‘wobbly’, also ‘wobbler’, denotes a fit of temper or panic