Insult set out to be most modest (9)
I believe the answer is:
slightest
'modest' is the definition.
Both the definition and answer are superlative adjectives. Maybe there's a link between them I don't understand?
'insult set out to be most' is the wordplay.
I cannot quite see how this works, but
'insult' could be 'slight' (I've seen this in another clue) and 'slight' is found in the answer.
an anagram of 'set' is 'est' which is present in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for slightest that I've seen before include "Most tenuous or smallest" , "carrying least weight?" , "least important" , "Most tenuous or meagre" .)