To be at the apogee of the sexual act; to be fully inserted into one's partner. Said to be from the data plate found on the sides of various pieces of hydraulic drilling equipment. To be up to your nuts in guts, to bottom out.
Chuck was up to the maker's mark in Cindy last night - that must explain why she's walking funny today. - Sol R.
by Pontius Pilate August 15, 2006
Can you define these popular missing words?