A much cooler way to say "thumbs up"
You can chug a gallon of milk? Upthumbs!
by Dr. Seuss, PhD July 19, 2011
1 more definition
when you go on urban dictionary and give your own definition a thumbs up, and you give everyone above you a down thumb
It's time to go upthumb my definition!
by BAMF- emma March 06, 2008