»banjaxed
Thanks to the esteemed Mr O Connor, I was reminded of banjax, verb:
banjaxes, banjaxed, banjaxing
1. To ruin, stymie or destroy.
Etymology: 1930s: Anglo-Irish.
But what else did you expect from swearing dot org? Google Print cites a half-dozen works for banjax, but three are dictionaries!