Encourage onboard medical professionals (8)
I believe the answer is:
surgeons
'professionals' is the definition.
(surgeon is a kind of professional)
'encourage onboard medical' is the wordplay.
I cannot quite understand how this works, but
'encourage' could be 'urgeon' (urging on is a kind of encouraging) and 'urgeon' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for surgeons that I've seen is " Medical operators".)