obby 

In Roblox, a obstacle course.
In Minecraft, obby is short for obsidian, commonly used on faction servers.

Roblox:

Player1: Hey kid, do you want to play a obby?

Noob: N0 thx m8 i b4d at 0🅱🅱ys xD lit saveage famm

Minecraft:

Player1: Anybody selling some obby? I need to build a new base.

Player2: I'll sell ya a stack of obby for 50,000.

obby by LitBot May 7, 2018

obby 

Short for obstacle course. Often used on the website "ROBLOX".

lets got to that obby

obby by anotherusername1111 February 13, 2010

obby 

For Roblox: Obstacle course

You: Hey wanna go to the easiest obby?
Noob: What's an obby?

obby by Octus The Robot May 24, 2011

obby 

Obby= o bby= oh baby.
Pronounced: aw bee.

See:oh baby,babeh.

Guy: *smacks ass*
Girl: obby!

obby by Jay :3 June 23, 2008

obby 

Obsidian in the game minecraft

Hey im gonna go mine obby for our big grief on infinium

obby by SnowballGaming November 16, 2011

Obby 

A klepto thief who uses piss vapour to distract you from when he steals shit.

You: Obby, you smell like piss. Hey! Where the heck is my black marker?

Obby by Bahati September 14, 2007

Obby 

Slang for dickhead, loser, idiot.

Man, that skank is acting obby-ish.

Obby by SlappyMcGee August 28, 2006