Shrinking section of government? I'm idealistic! (5)
I believe the answer is:
timid
'shrinking' is the definition.
(thesaurus)
'section of government? i'm idealistic' is the wordplay.
'section of' indicates a hidden word.
'TIMID' can be found hidden inside 'government im idealistic'.
(Other definitions for timid that I've seen before include "Diffident, faint-hearted" , "afraid to speak out?" , "Nervous and easily alarmed" , "Easily alarmed, shy" , "Easily frightened" .)