The word was "Brobdingnagian", which apparently means "giant", from the book, Brobdingnag, published in the 1700s. I know all of the words you listed, even if I don't know t he books they came from, on the other hand, I've never heard anyone use "Brobdingnagian" and I've never heard of the book it came from either.
I don't know that one, but I do know gargantuan, and pantagruelian, which come from a 17th century novel by Rabelais as well as yahoo and Lilliputian, which come from a 1726 novel by Swift.
Strangely, I knew this one. Once you hear this word it refuses to leave your head.