Royalty of whom people gas heartlessly? (5)
I believe the answer is:
kings
'royalty of whom' is the definition.
I can't tell whether this defines the answer.
'people gas heartlessly?' is the wordplay.
'people' becomes 'kin' (I've seen this in other clues**).
'heartlessly?' suggests removing the centre (I've seen 'heartlessly' mean this).
'gas' with its middle removed is 'gs'.
'kin'+'gs'='KINGS'
Can you help me to learn more?
(Other definitions for kings that I've seen before include "Cambridge college" , "Monarchs" , "a couple of books" , "Not subjects among those" , "Lynn may follow in > college" .)