2-thumbin Share definition Flag What experienced texters do in order to text faster. (Needless to say, the texter uses 2 thumbs) Man, I just sent the message and she already replied. she must be 2-thumbin. 2-thumbin by Challenge December 12, 2009 0 0 Get merch Get the 2-thumbin mug. Buy Now — $32.95 See more merch