Attendants - we dart about in ship (8)
I believe the answer is:
'attendants' is the definition.
(steward is a kind of attendant)
'we dart about in ship' is the wordplay.
'about' indicates an anagram.
'in' indicates putting letters inside.
'ship' becomes 'SS' (prefix in ship names eg SS Great Britain).
'wedart' anagrammed gives 'teward'.
'teward' inserted into 'ss' is 'STEWARDS'.
(Other definitions for stewards that I've seen before include "Racing authorities" , "They look after passengers on aircraft or ship" , "They look after passengers on aircraft and ships" , "Crew members" , "waiters" .)