In the context of an (MMO)RPG:

1. Usually refers to the casting classes, i.e. the ones that rely on magic instead of melee.

2. Generally the term applies to any character class that delivers more attack damage than, yet will nevertheless lose in a 1 vs 1 fight to, some standard garden-variety warrior.

Kiting is a glass cannon's best friend.
Warrior1: Dude, I just killed like 10 wizards, woot.

Warrior2: SFW dude, they're glass cannons, and they had already used up all their spells.
by majorcatass August 16, 2007
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A girl with great looks but little to no substance; a weak constitution. These girls are generally shallow and usually fall for the "bad boys," which are the boys that treat her like crap so she has to constantly qualify and validate herself.
Dude, don't go for Tomi. She's a glass cannon.
by pydrasparadox August 6, 2020
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Someone who has no issue criticizing others, often to an extreme extent, but gets extremely defensive when he is under criticism.
He’s a glass cannon critic, which is why we hate him.
by Salvguard January 12, 2020
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A moderation system in which it is effectively a glass cannon, usually consisting of slight discrepancies or bias to result in a mishap in servers.

This is most common in communities with corrupt moderation teams or outright bad ones.
Otis: "bro did you get banned from the forum"
Paul: "yeah, their Glass Cannon Moderation banned me for something slightly inappropriate when he wrote 3 troll posts"
by Not AstroSoup_ May 6, 2022
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tailow
damn thats a glass cannon
by twwhw February 6, 2022
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EVE Onlines bombers, like Nemesis.
Person 1: dude there’s a Nemesis on D-Scan.
Dude: don’t worry it’s a glass cannon, you should be able to blow it up
by VesperTheCoffeeAddict August 2, 2022
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