Ship's officers tie alien up as stowaway would be? (8)
I believe the answer is:
stewards
'ship's officers' is the definition.
'tie alien up as stowaway would be?' is the wordplay.
I cannot quite see how this works, but
'would' could be 'd' (I've seen this in other clues) and 'd' is found within the answer.
'be?' could be 'stew' (stewing is a kind of being) and 'stew' is found in the answer.
This may be the basis of clue (or it may be nonsense).
(Other definitions for stewards that I've seen before include "Crew members" , "They look after passengers on aircraft or ship" , "They look after passengers on aircraft and ships" , "Those who manage property, etc for someone else" , "Racing authorities" .)