Way out of planet (4)
I believe the answer is:
lane
'way' is the definition.
(I know that lane is a type of way)
'out of planet' is the wordplay.
'out of' indicates the answer is hidden within the clue.
'LANE' is hidden within 'planet'.
(Other definitions for lane that I've seen before include "Narrow rural road" , "Byroad" , "Footpath" , "Quiet road" , "Passage" .)