|Origin:||cotton 'to be successful' (16-19 centuries), perhaps from cotton (of cloth) 'to form a soft surface' (15-19 centuries), from COTTON1|
cotton onphrasal verb
It took me a while to cotton on.
cotton on to
Sarah soon cottoned on to what he was trying to do.
cotton to somebody/somethingphrasal verb
I didn't cotton to her at first, but she's really nice.