Get tender initially with US soldier on return (4)
I believe the answer is:
twig
'get' is the definition.
(thesaurus)
'tender initially with us soldier on return' is the wordplay.
'initially' says to take the initial letters.
'with' becomes 'w' (abbreviation).
'us soldier' becomes 'gi' (I've seen this in other clues).
'on return' shows that the letters should be reversed in order.
The first letter of 'tender' is 't'.
'gi' in reverse letter order is 'ig'.
't'+'w'+'ig'='TWIG'
(Other definitions for twig that I've seen before include "Finally understand" , "Suddenly comprehend" , "A small branch - cop on?" , "Informally grasp meaning" , "Suddenly see; branchlet" .)