Barber shop with no work to declare (6)
I believe the answer is:
Here is my best explanation:
'barber' is the definition.
'shop with no work to declare' is the wordplay.
'with no' suggests deleting specific letters.
'work' becomes 'op' (abbreviation for opus).
'to declare' becomes 'aver' (averring is a kind of declaring).
'shop' with 'op' removed is 'sh'.
(Other definitions for shaver that I've seen before include "Young lad (dated); razor", "Hair remover", "young man", "Boy < barber", "Youth", "A razor or its user", "Razor", "Electric razor", "youngster once" and "little boy".)