US soldier about to enter drop breathed deeply (6)
I believe the answer is:
sighed
'breathed deeply' is the definition.
'sighed' can be an answer for 'breathed' (sighing is a kind of breathing). I am not certain of the 'deeply' bit.
'us soldier about to enter drop' is the wordplay.
'us soldier' becomes 'gi' (I've seen this in other clues).
'about' is a reversal indicator.
'to enter' means one lot of letters goes inside another.
'drop' becomes 'shed' ('shed' can be a synonym of 'drop'**).
'gi' written backwards gives 'ig'.
'ig' put inside 'shed' is 'SIGHED'.
Can you help me to learn more?
(Other definitions for sighed that I've seen before include "Exhaled softly and sadly" , "expressed resignation, say" , "fed up" , "Sounded dejected" , "Made sad sound" .)