Shrubbery gets a polish (3)
I believe the answer is:
rub
'a polish' is the definition.
(polish meaning rub to make shiny)
'shrubbery gets' is the wordplay.
'gets' says the answer is hidden in the clue.
'RUB' can be found hidden inside 'shrubbery'.
(Other definitions for rub that I've seen before include "Remove marks - ... out" , "Irritate-...the wrong way" , "Apply friction to - difficulty" , "Ointment for skin" , "Massage or buff" .)