However, if you're looking for a word that uses the root "pair" in a different form, here are a few options:
* Unpaired - meaning not paired or matched.
* Pairing - the act of forming pairs.
* Paired - past tense of "to pair".
* Pairwise - done or occurring in pairs.
* Bipartite - divided into two parts. (This word uses the root "part" but can be considered a related concept to "pair").
Let me know if you have another specific requirement for the word, and I can try to come up with something more specific.