a night on the town heavily drinking with your friends, pub crawling.

Heavy Drinking, usually at night time and purpotrated by a group of "lads", although females occasionally can join.

to go out have a good time drink loads, smoking loads, and bantering and pulling loads of people

lash means 2 have raw sex

wen u b lashin a mandem/galdem
ur basically avin sex init
standard procedure

1. Lashings of: a large amount of, used mainly to refer to things like cream, custard etc.
2. Lash: to strike with a whip
3. Lash together: to bind together with ropes etc
4. To get lashed: this is simply to get very drunk/pissed inebriated/sloshed/hammered/legless/rat-arsed /etc. Lash can also be used as a noun meaning alcohol.

As in: 'Hey, do you fancy going out and getting lashed tonight?'