A large quantity of something, usu. intended to be greater than hugantic
but regardless is referring to multiple items or actions.
All right, recruit--I'd better see me a metric butt ton of shoe polish on those boots or I'm gonna rip you a new one!
I'm afraid I can't join you and the lads for the croquet match today, as I have a metric butt ton of wallhangings to color-coordinate before the Gimp arrives this evening.