First aid accepted by soldiers? (6)
I believe the answer is:
maiden
'first' is the definition.
(as in a maiden voyage)
'aid accepted by soldiers?' is the wordplay.
'accepted by' indicates putting letters inside.
'soldiers?' becomes 'men' (men can mean a group of soldiers).
'aid' put inside 'men' is 'MAIDEN'.
(Other definitions for maiden that I've seen before include "When you get her" , "First, inaugural" , "Miss" , "To the rear (of a ship)" , "Earliest - unmarried" .)