Also known as a blank or rag, a brick is a community card (either the turn or river) that seemingly does not affect anyone’s range of hands. It is the exact opposite of an Action Card, as it probably does not improve many hands, thus not creating much additional action.
Example: The flop is 789, David bets and is called by one player. The turn is a brick, an off-suit 2. David checks and his opponent checks behind.