Definitions of pair:

• noun:   a poker hand with 2 cards of the same value
• noun:   two people considered as a unit
• noun:   a set of two similar things considered as a unit
• noun:   two items of the same kind
• verb:   form a pair or pairs

  Example: "The two old friends paired off"

• verb:   arrange in pairs

  Example: "Pair these numbers"

• verb:   occur in pairs
• verb:   make love
• verb:   bring two objects, ideas, or people together

  Example: "The student was paired with a partner for collaboration on the project"

• name:  A surname (rare: 1 in 100000 families; popularity rank in the U.S.: #11481)