Know how to use "fewer" and "less"? Find out.
1560s, "quibble, evasion," of unknown origin, perhaps connected to German quer (see queer (adj.)) via notion of twisting and slanting; but its earliest appearance in western England dialect seems to argue against this source. Perhaps originally a technical term for a twist or flourish in weaving. Sense of "peculiarity" is c.1600.