unemployment and other economic 'variables'
The loan has a 'variable' interest rate.
The winds were light and 'variable'.
(..) Do you think I'm not? Why did Fury call us in? Why now? Why not before? What isn't he telling us? I can't do the equation unless I have all the variables. You think Fury's hiding something? He's a spy. Captain, he's "the" spy. His secrets have secrets. It's bugging him, too. Isn't it? (..)2012 The Avengers