The term 'go on about' can be defined as talking or writing at length about a particular subject. The crossword solutions for this term are RANT (4 letters), COMPLAIN (8 letters), and RAVE (4 letters). Ranting is an intense form of complaining, often done in an angry or passionate manner. Complaining is expressing dissatisfaction or annoyance about something. Raving is speaking or writing with great enthusiasm about something. All three words describe talking or writing at length about a particular subject, but the tone of the discussion varies depending on the word used.