From Longman Business Dictionarysell on phrasal verb [transitive]1 sell somebody on something American English to persuade someone to buy a particular thing or support a particular ideaMany consumers are sold on the company’s environmental message.With any new product, you have to sell consumers on the idea.2 sell something onCOMMERCE to sell something immediately after buying itsell something on to somebodyThe shares were sold on to another party. → sell→ See Verb table