lose-by Share definition Flag Pronounced loo-zz-bee. An alternate name for the sport called rugby. Ultimately, this sport is quite lose. Hence the name lose-by. S: why do you like lose-by? M: coz its win! S: nah... it's lose. lose-by by MikkaD March 27, 2009 0 0 Get merch Get the lose-by mug. Buy Now — $32.95 See more merch