To unhitch means to disconnect or unfasten something that was attached or hooked together. When farmers unhitch horses from a wagon, they remove the straps and chains connecting the animals to the load they were pulling. When you unhitch a trailer from a truck, you lift it off the hitch ball and unplug the lights.

Think of it as the opposite of hitching: if hitching joins two things together, unhitching separates them.

You might unhitch a rope from a post, unhitch a boat from its mooring, or unhitch a dog from its leash. The word suggests a deliberate action of freeing something that was secured or tied down. In the Old West, a traveler arriving at a town would unhitch their horse from their wagon before going into the general store, then hitch it back up when ready to leave. Today, people still unhitch recreational trailers at campgrounds so they can drive their trucks around freely.