Brick is an unofficial term used by players when they draw a hand with poor synergy, such as a hand with a lot of high Level monsters, a hand with no monsters, or a hand with mismatched draw cards. It is possible to reduce the odds of bricking by keeping the Deck size at or close to 40 cards, and by limiting the number of high Level monsters used.
Examples of Bricking in the Anime
In episode 190 of Yu-Gi-Oh!, Joey Wheeler draws an opening hand of "Landstar Shot", "Jinzo", "Red-Eyes B. Dragon", "Graceful Dice", "Polymerization", and "Hyper Refresh". Since he has no Level 4 or lower monsters in his hand, he is forced to pass without Summoning a monster.
In episode 22 of Yu-Gi-Oh! ARC-V, Yuya Sakaki draws an opening hand of "Odd-Eyes Pendulum Dragon", "Performapal Elephammer", "Performapal Springoose", "Performapal Kaleidoscorp", "Performapal Partnaga", and "Stargazer Magician". Since he has no Level 4 or lower monsters and cannot perform a Pendulum Summon, he is forced to pass without playing a card.