Wonder most of the soldiers returned (5)
I believe the answer is:
sight
'wonder' is the definition.
(thesaurus)
'most of the soldiers returned' is the wordplay.
'most of' means to remove the last letter.
'soldiers' becomes 'gis' (I've seen this in other clues**).
'returned' says the letters should be written backwards.
'the' with its last letter removed is 'th'.
'th'+'gis'='thgis'
'thgis' backwards is 'SIGHT'.
(Other definitions for sight that I've seen before include "Spot - eyesore" , "Looking" , "Observe" , "Aiming device on gun" , "good deal" .)