Ply with is a phrase that can mean different things depending on the context. It can mean to provide someone with something or to persuade them to do something. Some synonyms for this phrase include cater to, comply with, accommodate, satisfy, and indulge. If you are trying to provide someone with something, you can use synonyms like furnish, equip, outfit, or supply. On the other hand, if you want to persuade someone to do something, you can use synonyms like coax, convince, influence, or prevail upon. Whatever the context, there are always synonyms available for the phrase "ply with" to effectively convey your message.