The term 'convention ID' can be summarized as a name tag that is used to identify individuals at conventions. The crossword solution for this term is 'NAMETAG, ' which is a seven-letter word. Name tags are typically worn by attendees of conventions, conferences, and other large events in order to identify themselves and make it easier for others to recognize them. They are also used to help keep track of who is attending the event and to ensure that only authorized personnel are present.