This adjunct shows program finish time (9)
I believe the answer is:
appendage
'this adjunct' is the definition.
(thesaurus)
'program finish time' is the wordplay.
'program' becomes 'app' (type of computer program).
'finish' becomes 'end' ('end' can be a synonym of 'finish').
'time' becomes 'age' (age is a kind of time).
'app'+'end'+'age'='APPENDAGE'
'shows' acts as a link.
(Other definitions for appendage that I've seen before include "Thing attached to another" , "E.g. insect's leg, feeler" , "It's added or attached to a larger or more important part" , "Attached item" , "Addendum" .)