why do we say....

[Jascon]

A pair of underpants or a pair of knickers?

Surely you can't have one

[THECORBYLOON]

We say a pair or trousers and a pair of spectacles too. There is only one item but they each have two of something, legs, and lenses, hence they are a pair.

[Quizmonster]

Click here for the explanation.

[Peter Pedant]

Yeah a knickers nicker is some fella, leer, limp etc, who goes around taking them from washing lines.

P P