Had a look at that definition. I think it's wrong. Wrong wrong wrong. No wonder I was confused. Anyway, sorted.
Actually I take issue with a fair few of BRB's definitions of science/ maths words. I mean, obviously it's hardly the place to turn to if you want to get a grasp on the subject. But even so, they could at least try to make it correct. Take the definition of that ever-popular particle, the Higgs boson;
"A massive meson with zero spin ...".
The meson bit is just plain wrong - mesons have smaller particles inside them but the Higgs boson is thought to be a fundamental particle and, therfore, is not a meson. The Relativity definition perpetuates the myth that special relativity cannot handle acceleration, too. It can. Anyway, rant over.
All that said, thanks for pointing me to the definition. I'd finished the puzzle earlier this morning but felt that it was a bit short of what the word meant to me. With that definition I'm finally satisfied that my solution is complete.