Praise lieutenant after chopper comes back (5)
I believe the answer is:
exalt
'praise' is the definition.
(I know that exalt is a more specific form of praise)
'lieutenant after chopper comes back' is the wordplay.
'lieutenant' becomes 'lt' (abbreviation for lieutenant).
'after' says to put letters next to each other.
'chopper' becomes 'axe' (something which chops).
'comes back' is a reversal indicator.
'axe' reversed gives 'exa'.
'lt' put after 'exa' is 'EXALT'.
(Other definitions for exalt that I've seen before include "Promote" , "Elevate" , "Honour - raise up" , "Praise highly" , "Praise, glorify, or honour" .)