biff definition by Webster's New World
Origin: probably echoic
biff definition by American Heritage Dictionary
Informaltransitive verb biffed, biff·ing, biffs
Origin: From English biff, interjection, probably of imitative origin.
noun Upper Midwest
biff - Computer Definition
(Binary Interchange File Format) A spreadsheet file format that holds data and charts, introduced with Excel Version 2.2 in 1989.