Strain to get a look (3)
I believe the answer is:
air
I believe this clue is a double definition.
'strain' is the first definition.
(I know that strain can be written as air)
'a look' is the second definition.
(something might have a certain air or look)
'to get' acts as a link.
(Other definitions for air that I've seen before include "See 21" , "Atmosphere, manner" , "Lay" , "Element; tune" , "Short song" .)