The crossword solution for the term 'harass, with 'ON'' is RAG. To harass someone means to subject them to unwanted or persistent attention, typically of an intimidating or abusive nature. This can be done in a variety of ways, such as through verbal abuse, physical intimidation, or other forms of aggression. The term 'RAG ON' is a slang phrase that means to criticize or belittle someone. Therefore, the crossword solution of RAG is an appropriate answer for the term 'harass, with 'ON''.