pair in WordNet English dictionary

1. a set of two similar things considered as a unit
   pair  brace 
   
2. two items of the same kind
   couple  pair  twosome  twain  brace  span  yoke  couplet  distich  duo  duet  dyad  duad 
   
3. two people considered as a unit
   pair 
   
4. a poker hand with 2 cards of the same value
   pair 
   

1. engage in sexual intercourse
   "Birds mate in the Spring"
   copulate  mate  pair  couple 
   
2. bring two objects, ideas, or people together
   "This fact is coupled to the other one"; "Matchmaker, can you match my daughter with a nice young man?"; "The student was paired with a partner for collaboration on the project"
   match  mate  couple  pair  twin 
   
3. form a pair or pairs
   "The two old friends paired off"
   pair  pair off  partner off  couple 
   
4. arrange in pairs
   "Pair these numbers"
   pair  geminate 
   
5. occur in pairs
   pair  geminate