Unfamiliar; strange
I believe the answer is:
alien
I believe this clue is a double definition.
'unfamiliar' is the first definition.
(I've seen this before)
'strange' is the second definition.
(synonyms)
(Other definitions for alien that I've seen before include "One is from outer space, perhaps" , "extraneous" , "coming from overseas" , "Foreign - film directed by Ridley Scott" , "repugnant" .)