For every fellow, ten changes are lasting (9)
I believe the answer is:
permanent
'are lasting' is the definition.
(synonyms)
'for every fellow ten changes' is the wordplay.
'for every' becomes 'per' ('per' means 'for each' or 'for every').
'fellow' becomes 'man' (fellow can mean a man).
'changes' indicates anagramming the letters.
'ten' anagrammed gives 'ent'.
'per'+'man'+'ent'='PERMANENT'
(Other definitions for permanent that I've seen before include "Lasting for ever" , "not expected to change" , "Lasting, durable" , "Lasting, irreversible" , "indestructible" .)