Nay, if you be no better in the Reare then in the Van I shall make no doubt to vanquish, and vanquash you, too, before we part.
Dick of Devon (c1626)

The OED is boring. The definition there is “To Smash,” but that doesn’t really conjure the meaning I think of when I hear vanquash. It conjured the word vanquish (to deafeat, conquer) along with squash. If something has been vanquashed, it wasn’t just smashed, it was annihilated, (Check out Charles Hodgson’s excellent post/podcast on annihilate), hence my definition of SMASHTICATE.

It’s a very useful word, especially when describing incredible feats and defeats in history. Remember when the Rebels blew up the second Death Star? Empire got totally vanquashed.