Crumbles with seed or nuts (6)
I believe the answer is:
erodes
'crumbles' is the definition.
The answer and definition can be both related to change as well as being verbs in their -s form.
Perhaps there's an association between them I don't understand?
'with seed or nuts' is the wordplay.
'with' says to put letters next to each other.
'nuts' is an anagram indicator (nuts can mean crazy).
'seed' put next to 'or' is 'seedor'.
'seedor' with letters rearranged gives 'ERODES'.
Can you help me to learn more?
(Other definitions for erodes that I've seen before include "Wears away with weather" , "Wears away as by time or water" , "Eats away" .)