Definitionen
1.AdjectiveCarried or used on or in a vehicle or vessel.
2.AdjectiveBeing a part of, being included in, participating in."When it comes to security, everybody seems to be as onboard as I am.; James is onboard as a production manager."
3.AdverbOn or in a vehicle or vessel; aboard; on board.
4.VerbTo become a part of a group; to incorporate (someone) into a group.
5.VerbTo begin to use a product or service; to take (someone) on as a new customer of a product or service.