The n-gram viewer adjusts its vertical axis to make the data curve visible. The maximum y-axis value of the "fugazi" n-gram is 0.0000000500% or in round numbers, zero. If you add a common word -- I picked "psychology" -- the maximum shoots up to 0.00300%. "Psychology" is 60,000 times more common than "fugazi". In fact, the latter word doesn't shift the curve above zero when the two are plotted together. The big spike in the curve for "fugazi" alone could represent just a handful of publications.
I almost forgot to mention this: as far as I can remember, today is the first time I've ever seen that word.

English Teacher