'quirk' originates from Middle English or an uncertain/imitative origin; there is no single clearly documented source for the modern word.

'quirk' was recorded in the 16th century meaning 'a sudden twist or turn' and later extended to mean 'an odd or unexpected trait', eventually taking on the modern senses of 'peculiarity' and 'minor fault'.

Initially, it meant 'a sudden twist or turn', but over time it evolved into its current meaning of 'an odd habit, peculiarity, or minor irregularity'.