Wiktionary
vb. 1 (context transitive English) To put into pairs; to put into a group of two. 2 (context intransitive English) To get into pairs; to join together to make a group of two.
Usage examples of "pair up".
Even the natural obstinacy of Cedric sunk beneath these obstacles, where he, remaining on the point of junction, had the task of dragging a reluctant pair up to it, one with each hand.
It was the second session of Modern Living, and everyone in our class had to pair up and get married.
And if the two recessive genes pair up, it kills you before your first birthday.
If he'd been watching people pair up all weekend, while taking no relief for himself, he must be quite frustrated.
Mixtal gestured at Hal, and several warriors prodded the pair up the steep steps to the top of the pyramid.
The blast of the uproar they raised almost blew the fleeing pair up the steps of the tower.