What is Pair ?
Pair is (noun) 1. two things taken together a pair of socks a pair of gloves She’s bought a new pair of boots. these socks are a pair these socks go together 2. two things joined together to make a single one He took a pair of binoculars with him when he went out walking. I’m looking for a clean pair of trousers. Where’s my pair of green shorts? This pair of scissors is blunt. 3. two rowers in a boat The British pair won the silver medal. 4. (in the House of Commons) a Member of Parliament who has an agreement with a Member of Parliament from the opposite party not to vote if either is absent from Parliament (verb) to pair up to join with another person to do something Everyone paired up for the treasure hunt.
source: Easier English, Student Dictionary Upper Intermediate Level