Unknown drone flying around over there (6)
I believe the answer is:
yonder
'over there' is the definition.
(I've seen this before)
'unknown drone flying' is the wordplay.
'unknown' becomes 'y' (algebra**).
'flying' indicates anagramming the letters.
'drone' is an anagram of 'onder'.
'y'+'onder'='YONDER'
'around' acts as a link.
(Other definitions for yonder that I've seen before include "Over there, somewhat archaic" , "Rodney (anag.)" , "At a distance but in sight" , "Over there, of old." , "See Rodney over there" .)