Why are some things which are singular....

[osprey]

referred to as being plural? For instance, we talk about a pair of trousers when there is only the one item.

[THECORBYLOON]

An article consisting of two joined or corresponding parts such as trousers or spectacles, for example, are called pairs. Trousers have two legs (as do spectacles as it happens) hence a pair of trousers.

[Quizmonster]

Click here for a detailed explanation.

[jno]

spectacles have two legs? Personally, if I make a spectacle of myself, it's usually because I'm legless.

[brifos]

Well done, jno!

[shaneystar2]

...My specs have two legs!! ....I wondered why they keep walking off and I can never find them !