A pair born to compete (5)
I believe the answer is:
brace
'a pair' is the definition.
(I know that pair can be written as brace)
'born to compete' is the wordplay.
'born' becomes 'b' (abbreviation next to the year of someone's birth).
'to compete' becomes 'race' (racing is a kind of competing).
'b'+'race'='BRACE'
(Other definitions for brace that I've seen before include "double" , "Two of a kind" , "prepare for impact" , "Support - pair" , "Secure" .)