Streamlined (5)
'streamlined' is the definition.
(streamlined for travel through air)
This is all the clue.
(Other definitions for aerodynamic that I've seen before include "Having a drag-reducing shape" , "Streamlined" , "very good on air?" , "Fit to be a high-flyer" , "could be made to fly?" .)
'streamlined' is the definition.
(I know that streamlined can be written as sleek)
This is the entire clue.
(Other definitions for sleek that I've seen before include "with glossy coats" , "Aerodynamic - well-groomed" , "Smooth and shiny" , "Smooth - well-fed" , "Pleasingly smooth" .)