“Degen” is short for the colloquial term “degenerate” as in “degenerate gamer”. In the world of bitcoin, it is someone who likes to take out loans against their bitcoin with the aim of buying more bitcoin or shitcoins with their loan money.
Needless to say, this strategy is high risk at the best of times and some would say reckless. If there were sudden price movements, they would undoubtedly rek and lose all their Bitcoins.
Unfortunately, some people take out loans using all their savings and it’s essentially a gamble, looking to turn their lives around in a matter of days. It doesn’t end well for many, leading to the usual FUD stories you see in mainstream media.