Conventioneer (noun)

1. A person who attends a convention, especially a trade or political convention.
2. A participant in a convention or meeting.

Origin:

From the french word 'conventionner' meaning 'to come together', derived from 'convenir' meaning 'to agree' + '-tion' (english suffix meaning 'an action or process').

Examples:

1. The conventioneer was excited to hear the keynote speaker.
2. Many conventioneers came from all over the world to attend the event.
3. The conventioneer was dressed in business attire.
4. She was a first-time conventioneer and was eager to network.
5. The conventioneer was impressed with the level of organization at the event.