A very loud etc, move with result (6)
I believe the answer is:
affect
'result' is the definition.
The answer and definition can be both to do with fundamental existence as well as being verbs in their base form.
Perhaps they are linked in a way I don't understand?
'a very loud etc move' is the wordplay.
'very loud' becomes 'ff' (musical abbreviation).
'move' is an anagram indicator.
'etc' is an anagram of 'ect'.
'a'+'ff'+'ect'='AFFECT'
'with' is the link.
Can you help me to learn more?
(Other definitions for affect that I've seen before include "Have repercussions on" , "Influence; make pretence of" , "Assume" , "Put on" , "attack" .)