USA, 1981—said to have been invented by cheerleader ‘Krazy George’—popularised worldwide during the 1986 FIFA World Cup in Mexico, as a translation of Spanish ‘ola’—hence the British phrase ‘Mexican wave’ (1986)
the practice of coasting downhill in a motor vehicle, with the engine disengaged—USA, 1949, lorry-drivers’ slang—one of the phrases in which ‘Mexican’ denotes basic devices or processes compared unfavourably with more advanced equivalents
USA, 1955—diarrhoea suffered by travellers, especially in Mexico—alludes to the Aztec emperor Montezuma II (c.1466-1520), who was captured by the Spanish and died in captivity
a situation in which neither side in an argument or contest can win—in early use: a situation in which a person loses their money, but saves their life—origin: an 1876 story in which a Mexican bandit robs a traveller from the USA, but lets him escape with his life