Pronounced "plan to".
A planned sex partner. Often a person from out of town, with whom one has not actually slept but "plans to" upon one's next visit.
Guy 1: I haven't had sex in months.
Guy 2: Should I tell that skank to come talk to you?
Guy 1: Nah, it's cool. I'm visiting my hometown soon, and I have a planto I can take to a hotel room if I get desperate.
Plantoleum is a noun derived from combining the Latin words "planta" (plant) and "oleum" (oil). Thus, this is a word for "plant oil" which is in contrast to and to distinguish from the word petroleum which is derived from combining the Latin words "petra" (rock) and "oleum" (oil) so that petroleum is a word for "rock oil". This is important since many different plant oils are now beginning to be used as fuels.
I prefer using plantoleum rather than petroleum as a fuel for my car because it is less polluting.