Cause an egghead wild anger (6)
I believe the answer is:
enrage
'cause' is the definition.
Although both the answer and definition are verbs in their base form, I cannot see how one could define the other.
'an egghead wild anger' is the wordplay.
'an egghead' becomes 'e' (head letter of 'egg').
'wild' indicates anagramming the letters.
'anger' is an anagram of 'nrage'.
'e'+'nrage'='ENRAGE'
Can you help me to learn more?
(Other definitions for enrage that I've seen before include "Revolutionary group in Paris" , "Drive to anger" , "Greatly annoy" , "Greatly anger" , "Genera (anag.)" .)