Possible Clues:

• South American cowboy
• Outlaw's advertisement banned in default
• Break one's promises
• Default, welsh
• Renounce Frenchman, say, on the way up
• Play a card out of suit
• Degenerate holding back default
• Don't follow suit — change to green energy
• Welsh Frenchman, Gaston Evans by initials
• Go back on promise arising in naive generosity