detach
To separate something from what it is attached to.
To detach means to separate something from what it's connected to, or to remove yourself emotionally from a situation. When you detach a trailer from a truck, you disconnect it so it stands alone. When you detach a page from a notebook, you carefully tear it out along the perforated edge.
The word often suggests a deliberate, controlled separation rather than a violent break. A submarine might detach from its docking station and quietly slip away. A scientist detaches a small sample from a larger specimen to study it under a microscope.
People can also detach emotionally. When a coach detaches from the stress of a close game, she steps back mentally to think more clearly about strategy. When someone feels detached from their friends, they feel disconnected or distant, like they're watching from outside instead of being fully part of the group.
The opposite of detach is attach. Notice how the prefix “de-” reverses the meaning, like how “defrost” means to reverse freezing or “deflate” means to reverse inflation. Something detachable is designed to come apart easily, like the detachable hood on a winter jacket.