Mr. X is the male version of the letter "X" in the English alphabet. Mrs. or Ms. X is the female version. Since they have no genitalia it is hard to differentiate between the two.
another term for a station wagon, mini-van, or any other kind of vehicle that is targeted at the "family" demographic(also M.A.V.)
"Tactical advantages aside, the M.A.V. is top of the line for the holy warrior troop transport manufactured by the Church of Latter Day Saints Military Industrial Complex. Also great for family trips...to heathen lands."