Gamble on Raymond and Alistair showing disloyalty (8)
I believe the answer is:
betrayal
'disloyalty' is the definition.
(betrayal is a kind of disloyalty)
'gamble on raymond and alistair' is the wordplay.
'gamble' becomes 'bet' (bet is a kind of gamble).
'on' means one lot of letters go next to another.
'raymond' becomes 'ray' (I've seen this in other clues).
'and' says to put letters next to each other.
'alistair' becomes 'al' (I can't justify this - if you can you should believe this answer much more).
'bet'+'ray'+'al'='BETRAYAL'
'showing' acts as a link.
Can you help me to learn more?
(Other definitions for betrayal that I've seen before include "sale" , "Breach of trust" , "Treacherous act" , "Act of treachery" , "Selling" .)