1) This is when a group of people try to move a heavy object and the last resort is a combined grunting effort, that actually moves the object.
2) Pertaining to a person that cannot relieve flatulence in a normal manner, wherein, he resorts to grunting as the last resort for the relief thereof.
3) This technique can also work for popping one's ears, as grunting forces the pop.
1) Man, did you see that tug-of-rope tournament? Yes, I did, Darly. Our team won when the fat guy swayed the team in our favor by way of Gruntrifical Force.
2) Johnny used Gruntrifical Force to fart when other options would not suffice.
3) Terry had the worst cauliflower ear. Due to his cauliflower ear, fluid built up in his ears, not only the outside of the ears, but the eardrums themselves. The poor bastard, now, has to pop them by using Gruntrifical Force.