biro lad Share definition Flag when in the library at university you observe someone who goes through an entire biro pen in 13 hours. True lad. Dude did you see that biro lad? He's on biro number 2 and its only 8pm! biro lad by cheeky charlie 18 January 17, 2011 0 0 Get merch Get the biro lad mug. Buy Now — $32.95 See more merch