Avoidance of oddball so naive (7)
I believe the answer is:
evasion
'avoidance' is the definition.
(thesaurus)
'oddball so naive' is the wordplay.
'oddball' is an anagram indicator (I've seen this in other clues).
'so'+'naive'='sonaive'
'sonaive' anagrammed gives 'EVASION'.
'of' acts as a link.
(Other definitions for evasion that I've seen before include "Subterfuge" , "Circumvention" , "Avoidance; equivocation" , "Hedging" , "prevaricating excuse" .)