Glass cannon defenders

that sucker hits hard i you don't have a good dark

From the name itself, glass cannons are basically hard hitting Pokémon with poor stamina pool. Hence the name. They hit hard but easy to shatter. Nevertheless, they'll definitely destroy any unprepared attacker or at least cause major damage before fainting.

Don't feel ashamed buddy. You're not the only one and as it's nowhere described I'm sure multiple were wondering the same.

Just to add to some great answers, a glass cannon might hit as hard as, for example, a Dragonite or even a Tyranitar, but it's typically low HP means it survival rate is much lower if takes a hit. For example, I was driving my Gym Trainer stats up today and attacking a 2700k Gyarados (which some call a glass cannon), and a 3100 (or thereabouts) Espeon with a 2600 Jolteon. The Jolteon could "just" manage to take out both of these two higher CP gym defenders even though at least one charge move from either defender, particularly the Espeon with Future Sight, would easily destroy the Jolteon. So glass cannons have killer moves, but lousy HP or stamina typically I suppose. Alakazam & Gengar also fit in this category, and Cloyster, Jynx are a good candidates as they are specialist attackers (ice moves against D'nites) with, again,relatively low HP. They can do a one-on-one with the Tier 1 Pokemon, but cannot take as much damage.