Revolutionary claim about a drug (8)
I believe the answer is:
chemical
'a drug' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'revolutionary claim about' is the wordplay.
'revolutionary' becomes 'che' (Che Guevara the Marxist revolutionary).
'about' indicates an anagram.
'claim' with letters rearranged gives 'mical'.
'che'+'mical'='CHEMICAL'
Can you help me to learn more?
(Other definitions for chemical that I've seen before include "Of a substance such as ethanol" , "Chic male (anag.)" , "Relating to composition and properties of substances" , "Material produced by a reaction involving changes in atoms or molecules" , "substance produced in a lab" .)