Constant changing of fads and taste (9)
I believe the answer is:
steadfast
'constant' is the definition.
(similar in meaning)
'of fads and taste' is the wordplay.
'of' is an anagram indicator (the answer comes from or 'of' the letters).
'and' means one lot of letters go next to another.
'fads'+'taste'='fadstaste'
'fadstaste' with letters rearranged gives 'STEADFAST'.
'changing' is the link.
I am not very happy about this link. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for steadfast that I've seen before include "Resolutely firm" , "Firm and dependable" , "Constant; true" , "Constant and resolute" , "Constant, not changing or yielding" .)