A fine assessed as a penalty for an infraction is generally considered justifiable. Fraud, on the other hand, is wrong—it's just the sort of thing that deserves a fine. So in mulct we have a unique word, one that means both "to fine" and "to defraud." The "fine" sense came first. Mulct was borrowed from the Latin word for a fine, which is multa or mulcta. The "fine" sense is still in use, mostly in legal contexts ("the court mulcted the defendant for punitive damages"), but these days mulct is more often used for an illegal act. It has been speculated that the use may have come about by association with the verb milk, in its sense "to exploit, to coerce profit from" (as in "she was milked by the lawyers for everything she had"), but that speculation has never been proven.
Examples of mulct in a Sentence
Noun
the loan shark usually imposed a mulct of an additional 20% on overdue payments
Verb
trying to mulct the insurance company for an accident that never happened