Megalasesh 

The colloquial title for a large meeting of an official body or period devoted to a particular activity.

"Is everyone prepared for the week long megalasesh?" "With so many people being involved, this will be such a megalasesh" "Let's have a move marathon megalasesh" "It is time for the D&D megalasesh"

Megalasesh by Jai-Bomb December 22, 2014

Megalash 

A night of drinking, and drinking alone.

Going on the lash is okay for Friday nights or Saturday nights. But the megalash is for a night to end all nights. Where you pound down full bottles of vodka, where your pres start with shots and beer bongs, and you end up in a gutter by the end of the night.

Me: We going out tonight?
Mate: Ye, on the fucking megalash, mate. Let's get fucking rekt.

Megalash by BingoBongoLand November 17, 2017