- Span is used esp. of a pair of horses harnessed together
- Yoke applies to a pair of animals harnessed together for pulling a yoke of oxen
- A brace , meaning two of a kind, applies esp. to certain animals or game birds a brace of pheasants, hounds, etc.
- Couple applies to any two things of the same sort that are somehow associated a couple of dollars, or is used colloquially to mean several or a few I have to buy a couple of things
- Pair is used of two similar or corresponding things that are associated together or are necessary in twos for proper use a pair of socks or of a single thing made up of two corresponding parts a pair of scissors