/spi'fee/ adj. 1. Said of programs having a pretty, clever, or exceptionally well-designed interface. "Have you seen the spiffy X version of empire yet?" 2. Said sarcastically of a program that is perceived to have little more than a flashy interface going for it. Which meaning should be drawn depends delicately on tone of voice and context. This word was common mainstream slang during the 1940s, in a sense close to #1.