Soldier gives first live performance (3)
I believe the answer is:
gig
'live performance' is the definition.
(I've seen this before)
'soldier gives first' is the wordplay.
'soldier' becomes 'gi' (term for US soldier).
'gives first' becomes 'g' (gst letter of 'gives').
'gi'+'g'='GIG'
(Other definitions for gig that I've seen before include "Date" , "A palindromic one-night performance" , "Palindromic one-night engagement" , "Live performance by musicians" , "Live musical performance" .)