A lass is Australian slang for a girl who hangs out with lads. lads are 'gangsta', the most popular people at boys schools. often seen drinking, smoking and vandalising. Lass's are bassicly lad's sluts, they wear to much makeup and have bleachedtrashy hair.
lad1: fuck bro, that lass is hot.
lad2: yeheshays.
a girl version of a lad. wears RL, nautica, tommy, Das, Nike, Lacoste ect. usually unwashed ratty ugly sluts but some lasses can pull it off and look bangin.