Look at torn page (4)
I believe the answer is:
gape
'look at' is the definition.
(thesaurus)
'torn page' is the wordplay.
'torn' indicates anagramming the letters.
'page' with letters rearranged gives 'GAPE'.
(Other definitions for gape that I've seen before include "Stare at page" , "Look amazed" , "Look in amazement or stupidity" , "wide opening" , "Failure to meet" .)