Forced frail cat I upset to eat one (10)
I believe the answer is:
artificial
'forced' is the definition.
(thesaurus)
'frail cat i upset to eat one' is the wordplay.
'upset' indicates an anagram.
'to eat' is an insertion indicator.
'one' becomes 'i' (Roman numeral).
'frail'+'cat'+'i'='frailcati'
'frailcati' anagrammed gives 'artficial'.
'artficial' enclosing 'i' is 'ARTIFICIAL'.
(Other definitions for artificial that I've seen before include "Contrived, false" , "Kiss of life" , "Bogus" , "Assumed" .)