"Weigh anchor" is a nautical term meaning to lift or hoist a ship’s anchor off the seabed in preparation for getting underway. It signifies the start of a journey and the transition from being anchored to sailing, originating from the Old English word wegan, meaning "to lift or carry".

Key details:
Action: It refers to hauling in the anchor chain or line, not measuring the weight of the anchor.

Anchors Aweigh: The moment the anchor lifts off the seabed, it is considered "aweigh".

Origin: Historically, crews used a capstan to lift the heavy anchor, sometimes working to the sound of a fiddle or song.

Usage: It means leaving a port or anchorage.

The phrase is distinct from "take in lines," which is used when a ship is tied to a dock, not anchored.