The phrase "pin on" means to attach or fasten something, typically with a pin or similar object. Some synonyms for "pin on" include affix, attach, clasp, clip, fasten, secure, stick, and tack. These words are all related to the act of joining or connecting one thing to another. "Pin on" is often used in the context of attaching a badge or brooch to clothing, but can also refer to fixing a note or reminder to a bulletin board or wall. By using synonyms for "pin on," one can add variety and nuance to their language and more effectively communicate their ideas.