The term 'not permanent' can be described by a variety of words, such as 'TEMPORARY' (9 letters), 'erasable' (8 letters), 'eradicable' (10 letters), 'acting' (6 letters), 'adhoc' (5 letters), 'protem' (6 letters), 'STOPGAP' (7 letters), 'FLEETING' (8 letters), and 'EPHEMERAL' (9 letters). These words all describe something that is not meant to last, or is only in effect for a short period of time. For example, 'TEMPORARY' implies something that is only in place for a limited amount of time, while 'FLEETING' suggests something that passes quickly. Similarly, 'EPHEMERAL' implies something that is short-lived and quickly fades away.