Fault is a related term of insult.
In obsolete|lang=en terms the difference between fault and insult
is that
fault is (obsolete) want; lack while
insult is (obsolete) the act of leaping on; onset; attack.
In lang=en terms the difference between fault and insult
is that
fault is to commit a mistake or error while
insult is to offend (someone) by being rude, insensitive or insolent; to demean or affront (someone).
As nouns the difference between fault and insult
is that
fault is a defect; something that detracts from perfection while
insult is an action or form of speech deliberately intended to be rude.
As verbs the difference between fault and insult
is that
fault is to criticize, blame or find fault with something or someone while
insult is (obsolete|intransitive) to behave in an obnoxious and superior manner (over, against).