stands for 'functional central limit theorem', and is synonymous with Donsker's theorem. Briefly: if {et} is a series of independent and mean zero random variables, partial sums (from 1 to T) of the e's converge to a standard Brownian motion process on [0,1] as T goes to infinity. See other sources for a proper formal stateme... Found on http://www.econterms.com/glossary.cgi?query=FCLT