Group participating in Monopoly react badly, beginning to lose (6)
I believe the answer is:
cartel
'group participating in monopoly' is the definition.
'cartel' can be an answer for 'monopoly' (I've seen this in another clue). I'm not sure about the 'group participating in' bit.
'react badly beginning to lose' is the wordplay.
'badly' indicates an anagram (letters in the wrong order).
'beginning to' indicates taking the first letters.
The first letter of 'lose' is 'l'.
'react' anagrammed gives 'carte'.
'carte'+'l'='CARTEL'
Can you help me to learn more?
(Other definitions for cartel that I've seen before include "Bloc" , "Firms operating together, illegally" , "Price-fixing group" , "Business combination to limit competition" , "Anti-competitive group for claret" .)