1) Much-feared earthquake 
[roller coaster] The Big One, formerly known or still commonly referred to as Pepsi Max Big One, is a steel roller coaster located at Pleasure Beach Blackpool in the United Kingdom. ==History== The Pepsi Max Big One was originally manufactured by Arrow Dynamics, a now defunct steel coaster manufacturer. Construction of the ride began in Sep...
(US Currency and Slang) - 1000 dollars. 'That'll cost you ten big ones!'
Big one is British slang for one hundred pounds sterling.
a one-thousand-dollar bill or the sum of one thousand dollars.