In British slang, a trump is a fart. Seriously, it's always meant that. We did not just make this up in
2016. Only of course BBC newsreaders have to try not to
giggle when they refer to the new
president.
When I was a kid we would tease our
friends when they farted. 'Eeurgh, you just
trumped!' Now I'm a grown-up citizen, we tease our American
friends when they elect a fart. 'Eeurgh, you just trumped! '