Refers to the vagina of one's mother. Relating to Homer's tale of Oedipus who killed his dad and unknowingly banged his mother.
Man 1: "I just got back from the gym with my mother."
Man 2: "For real? I bet that oedipussy is fire."
This word can have two different meanings.
The first definition is to date or have sexual relations with a woman who looks similar to or resembles your mother. Sometimes this can happen just because sometimes unrelated people can look similar or resemble family members. Sometimes a guy specifically seeks out a woman to date who resembles his mother, because he likes those qualities or he may have some underlying mother issues.
The second meaning (and the one most people think of when they use or see this word) is to date or have relations with your own mother. This is where the Oedi part of this word comes in. It is from the word Oedipus Complex, which in modern day terms means a condition where a male adult falls in love with his mother.
When the many rumors began circulating about me, that Ted Rimmel Jr is dating his mother. His mother is his girlfriend. These rumors always led to everyone putting two and two together, and figuring I was getting the Oedipussy.
Mitchell: "Have you heard the rumors that Ted Rimmel Jr's mother is his girlfriend?"
Heather: "I have heard, and I truly believe that is true."
Sandra: "Those rumors are all very true. Ted is so getting the Oedipussy."
Peter: "So you could say Ted is into the Oedipussy? Hahaha."