Art house I gathered, OK (9)
I believe the answer is:
authorise
'ok' is the definition.
('ok'->'authorize' is in my internal thesaurus and 'ize'->'ise')
'art house i gathered' is the wordplay.
'gathered' indicates an anagram.
'art'+'house'+'i'='arthousei'
'arthousei' anagrammed gives 'AUTHORISE'.
(Other definitions for authorise that I've seen before include "OK" , "Give power to or sanction" , "Sanction, empower" , "Give official permission to" , "commission" .)