Seldom found (4)
I believe the answer is:
rare
'seldom found' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for rare that I've seen before include "like gold dust" , "Scarce as hen's teeth!" , "Scarce or uncommon" , "Very, very occasional" , "Not easily come by like undercooked meat" .)