On-board Definition

adjective
(idiomatic) On or in a means of transportation.
Even when I am on board the plane, I can never feel secure that my luggage is, too.
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(idiomatic) Joining in or participating.

Is that new teammate properly on board yet?
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(idiomatic) Agreeing or supporting.

It's a good idea, but let's see if we can get a few more of the management team on board.
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adverb

On a vehicle or vessel; aboard.

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Synonyms: