Not of this earth (5)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
alien
'not of this earth' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for alien that I've seen before include "Foreign; extraterrestrial" , "One is from outer space, perhaps" , "Foreigner, outsider" , "Not native" , "extraneous" .)