Which informal logical fallacy is committed in the following argument? 'Mr. X used abusive language toward the child who threw a stone at his car. Since child abuse is a crime, he should be reported to the authorities.'

The argument trades on two different senses of the word 'abuse.'

'Abusive language' means harsh or insulting speech directed at someone.

'Child abuse' means the maltreatment of a child, a serious crime.

The reasoning shifts from the first sense to the second as if they were one.

Drawing a conclusion by sliding between meanings of a term is equivocation.