Once a hygienic, good-looking, popular, athletic man who in his youth, had the perfect girlfriend and was admired and envied for his wit and charm. But as he grew up and matured, this man turned into the complete opposite of what he was in his younger days. The delta male is referred to as a "has been" and is used to refer to the lowest caste of the hierarchical society. A delta male is subordinated to all others in the community and is in a continuous struggle of trying too hard to fit in a society where he no longer belongs.
I'd like to remember Marc for who he was in junior high, but it's just too bad he grew up to be such a delta male.
A Delta male is usually the prey of Alpha males. Delta males tend to be weak not only in physique, but also in mental capacity. Delta males usually enjoy being dominated and tormented by Alpha males, and usually go so far as paying for this treatment. Delta males are the most pathetic males in existence, closer to pansies than real men.
The polar opposite of an alpha-male. He has a clear lack of regard for sexual protection and genital grooming. He is typically an immigrant to the US, settles for work that is below minimum-wage, below janitorial work, and can often be found on Craigslist whoring his services for meager wages. Ugly women typically try to bear his children to lock him down.
You're so much better off without your loser ex-boyfriend who can't get a job--he's such a delta-male.