Soldiers accept German jobs (4)
I believe the answer is:
'jobs' is the definition.
(gig is a kind of job)
'soldiers accept german' is the wordplay.
'soldiers' becomes 'gis' (GI is an informal term for a US soldier).
'accept' means one lot of letters goes inside another.
'german' becomes 'g' (abbreviation).
'gis' going around 'g' is 'GIGS'.
(Other definitions for gigs that I've seen before include "One-night-stand musical performances" , "One-night music sessions" , "Pop/jazz band engagements" , "One-night musical stands" .)