A large quantity of something, usu. intended to be greater than hugantic or ginormous 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!

-or-

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.
by Macslacker February 4, 2006
Get the metric butt ton mug.
1.An amount that exceeds expectations of extremes, literally in metric weight.

2.an amount equal to a ton measured in increments of obese asses, usually for diorama purposes only.
by Alcaceltzer P. Grunt October 24, 2010
Get the Metric Butt-ton mug.