Witness attending examination in front of soldiers (8)
I believe the answer is:
attestor
'witness' is the definition.
(I've seen this before)
'attending examination in front of soldiers' is the wordplay.
'attending' becomes 'at' (I've seen this in other clues).
'examination' becomes 'test' ('test' can be a synonym of 'examination'**).
'in front of' says to put letters next to each other.
'soldiers' becomes 'or' (Other Rank).
'at'+'test'+'or'='ATTESTOR'
(Other definitions for attestor that I've seen before include "> witness" , "he'll swear!" , "One who enrolled" , "One giving evidence" , "Demonstrator" .)