The process of going down or eating out a woman's vagina. The vagina represents a dumpster with the individual performing the act thus representing a person(possibly a hobo or a trashman) getting trash out of the dumpster.
Jimmy got really drunk at that party and totally ended up going dumpster diving on Laura; she was quite ripe.
Looking for hook-ups or relationships, particularly with women, who use online dating sites or personals ads. (The logic being that almost any girl can get laid without having to advertise for it... and the ads are society's dumpster for those who can't.)
You can tell he met that skeezy chick on an online hook-up site. Yikes! But, hey, you can't expect to find qualitywhen you go dumpster diving.