To dismantle something means to take it apart piece by piece, carefully separating all the parts that were connected or attached. When you dismantle a bookshelf, you remove the shelves from their supports, unscrew the bolts, and separate all the boards until you're left with individual pieces. Mechanics dismantle engines to find problems or replace worn parts. When a family moves to a new house, they might dismantle the bunk beds so the pieces fit through doorways and into the moving truck.

The word suggests a methodical, deliberate process of taking something apart with purpose, often to understand how something works or to move it somewhere else. You dismantle carefully and systematically, working through each connection rather than smashing or breaking. Scientists might dismantle old equipment to study its design. A carpenter might dismantle an old deck before building a new one.

People also use dismantle in a broader sense, meaning to gradually destroy or end something complex. A new principal might dismantle an unfair policy at school by removing its rules one by one. When someone dismantles an argument, they're taking it apart logically to show why it doesn't work, examining each piece of reasoning until the whole thing falls apart.