tease: [OE] Tease originally meant ‘separate the fibres of wool’ (a sense still perceptible in the metaphorical tease out ‘disentangle something complicated’). It came from a prehistoric West Germanic *taisjan, whose base was also the source of English teasel [OE], a plant whose prickly flower heads were used for carding wool. The notion of ‘irritating someone with prickles’ led in the 17th century to tease being used for ‘pester’, which gradually weakened into ‘make fun of’.
