After good notice obtain appliance (6)
I believe the answer is:
gadget
'appliance' is the definition.
(synonyms)
'after good notice obtain' is the wordplay.
'after' means one lot of letters go next to another.
'good' becomes 'g' (abbreviation).
'notice' becomes 'ad' (short for advert).
'obtain' becomes 'get' (synonyms).
'g' next to 'ad' is 'gad'.
'gad'+'get'='GADGET'
(Other definitions for gadget that I've seen before include "Small mechanical device or tool" , "Clever device" , "appliance" , "Gizmo, contraption" , "Handy device" .)