when fat women wear their pants very high you cannot tell where their fat stops and their vagina starts. this large mound of fat in between is referred to as a valump.
1. (noun) Yet another slang word for booty. Only booties of immense size deserve this title. The root word of valumper is LUMP, which is referring to the lumps of the individualbooty cheeks.
2. Can also be used in verb form, "to valump"