A long term girlfriend who stays at your home. Similar to a stay at home mom or a housewife, with the exception that your not married & have no children. She cooks, cleans, plays with the dog, watches TV & fucks the shit out of ya when you come home. Typicly has the occasional part-time job, just to break up the boredom.
This does not mean some Gold digger or Skank who shacks up with you for a month or two, always bouncing from bed to bed with the frequency of a cheap Ham Radio.
The Stay At Home Girlfriend arrangement works as such: You pay all the bills & give her shoping money. She maintains your household & provides sexual favors. Works quite well really.
My ex-girlfriend Dani was a stay at home girlfriend.