It's more frightening needing to be in the barber's seat for longer? (7)
I believe the answer is:
hairier
I believe this is a double definition.
'it's more frightening' is the first definition.
(I've seen this before)
'needing to be in the barber's seat for longer?' is the second definition.
(having more hair)
(Other definitions for hairier that I've seen before include "More hirsute" , "Having more head cover" , "With more locks" , "more frightening" , "less safe?" .)