onboard

adjective

1. provided, occurring, etc., on a vehicle: among the ship’s many onboard services.
2. installed and functional within a vehicle or electronic device: onboard computers for aircraft.

verb (used with object) Business.

3. to assist and support (a new employee) in developing the skills, knowledge, attitudes, etc., needed to be successful in the job.
4. to interact and exchange information with (a new customer) so as to ensure customer satisfaction, maximize company revenue, etc.: Part of onboarding new clients involves setting expectations and timelines.

adj.1966 as one word, from on + board (n.2).