Beware aspect revealed (4,3)
I believe the answer is:
look out
'beware' is the definition.
(thesaurus)
'aspect revealed' is the wordplay.
'aspect' becomes 'look' ('look' can be a synonym of 'aspect'**).
'revealed' becomes 'out' (I've seen this in other clues).
'look'+'out'='LOOK-OUT'
(Other definitions for look out that I've seen before include "Beware!" , "Be watchful" , "Be on your guard!" , "Take care" , "as Wenceslas did" .)