Right, are few in number (4)
I believe the answer is:
rare
'few in number' is the definition.
'rare' can be an answer for 'few' (I've seen this in another clue). I'm not certain of the 'in number' bit.
'right are' is the wordplay.
'right' becomes 'r' (common abbreviation).
'r'+'are'='RARE'
Can you help me to learn more?
(Other definitions for rare that I've seen before include "few and far between" , "Unusual(ly fine)" , "Might steak be" , "Still red inside (as hens' teeth?)" , "Very infrequent or scarce" .)