Said of something that was previously fashionable or trendy (whether or not in the actual previous calendar year) but is not any longer. A: "Hey, I finally got those decals on my car that everyone was going crazy for!" B: "Pfft, please, those are so last year. No one cares about those any more!" A word of warning from our fashionistas—bell bottoms are so last year! If you want to look your absolute best, the new hottest craze is ruffled puffy shirts.