Watch we may receive, last of all (3)
I believe the answer is:
eye
'watch' is the definition.
(eye can mean to watch or look at)
'we may receive last of all' is the wordplay.
'last of all' indicates one should take the final letters.
The last letters of 'we may receive' are 'EYE'.
(Other definitions for eye that I've seen before include "See 1" , "Twenty four ac emphasises it" , "centre, of a sort" , "'Public' or 'private' body part" , "20 [OBSERVE]" .)