Beginner found in empty room (4)
I believe the answer is:
tyro
'beginner' is the definition.
(synonyms)
'in empty room' is the wordplay.
'in' says the answer is hidden in the clue.
'TYRO' can be found hidden inside 'empty room'.
'found' acts as a link.
(Other definitions for tyro that I've seen before include "Novice; Tory (anag.)" , "Initiate" , "Spell for rookie" , "Apprentice" , "Neophyte" .)