Not permanent (8)
'not permanent' is the definition.
('temporary' is the opposite to 'permanent')
This is the entire clue.
(Other definitions for temporary that I've seen before include "Short-lived" , "Stopgap" , "Portray me as being for a limited time only" , "Not for long" , "Not permanent or lasting" .)
'not permanent' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for erasable that I've seen before include "Capable of obliteration" , "Able to be rubbed out" , "that can be effaced" , "with potential to be wiped out" , "Like text" .)
(Another definition for adhoc that I've seen is " for this special purpose".)