hella \hel-LA\ adjective, adverb, noun, interjection: a lot of some thing. Example sentence: "That concert was hella tight, yo." No one truly knows the etymology of popular Northern California slang term "hella," only that it's so East Bay there's even a defunct prog metal band from Sacramento named for the term. Of course, Hella (the band) broke up. Merriam-Webster doesn't officially list the word, but any decent Urban Dictionary traces its roots to the Bay Area. Most recently, a UC Davis student nominated the popular term — which suburban teens have further bastardized as the PG-13 rated "hecka" — to be the official signifier of numbers with 27 zeros at the end of them. "Yotta" is the currently largest prefix in the International System of Units, serving numbers with 24 zeros. Hella units could be used to compute the Sun's wattage, New Scientist reported this spring. Scientists in control of International Committee for Weights and Measures say they'll superficially consider the proposal this September. But with 60,929 Facebook fans lobbying them, they better take it hella seriously.