<p><strong>Noun:</strong></p><ul><li>a device for securing a door, gate, lid, drawer, or the like in position when closed, consisting of a bolt or system of bolts propelled and withdrawn by a mechanism operated by a key, dial, etc.</li><li>a contrivance for fastening or securing something</li><li>(in a firearm) the mechanism that explodes the charge; gunlock</li><li>safety</li><li>any device or part for stopping temporarily the motion of a mechanism</li><li>an enclosed chamber in a canal, dam, etc., with gates at each end, for raising or lowering vessels from one level to another by admitting or releasing water</li><li>an air lock or decompression chamber</li><li>complete and unchallenged control; an unbreakable hold: The congresswoman has a lock on the senatorial nomination</li><li>slang: someone or something certain of success; sure thing: He's a lock to win the championship</li><li>wrestling: any of various holds, especially a hold secured on the arm, leg, or head: leg lock</li><li>horology: (in an escapement) the overlap between a tooth of an escape wheel and the surface of the pallet locking it</li><li>metalworking: a projection or recession in the mating face of a forging die</li></ul><p><strong>Verb (used with object):</strong></p><ul><li>locked</li><li>to fasten or secure (a door, window, building, etc.) by the operation of a lock or locks</li><li>to shut in a place fastened by a lock or locks, as for security or restraint</li><li>to make fast or immovable by or as if by a lock: He locked the steering wheel on his car</li><li>to make fast or immovable, as by engaging parts: to lock the wheels of a wagon</li><li>to join or unite firmly by interlinking or intertwining: to lock arms</li><li>to hold fast in an embrace: She was locked in his arms</li><li>to move (a ship) by means of a lock or locks, as in a canal (often followed by through, in, out, down, or up)</li><li>to furnish with locks, as a canal</li></ul><p><strong>Verb (used without object):</strong></p><ul><li>locked</li><li>to become locked: This door locks with a key</li><li>to become fastened, fixed, or interlocked: gears that lock into place</li><li>to go or pass by means of a lock or locks, as a vessel</li><li>to construct locks in waterways</li></ul><p><strong>Verb Phrase:</strong></p><ul><li>to keep out by or as if by a lock</li><li>to subject (employees) to a lockout</li><li>to commit unalterably: to lock in the nomination of the party's candidates</li><li>(of an investor) to be unable or unwilling to sell or shift securities</li><li>to imprison for a crime</li><li>printing: to make (type) immovable in a chase by securing the quoins</li><li>to fasten or secure with a lock or locks</li><li>to lock the doors of a house, automobile, etc.</li><li>to fasten or fix firmly, as by engaging parts</li><li>to track or follow a target or object automatically by radar or other electronic means</li><li>(in a video game) to target and then maintain the focus of the game camera and the player’s weapon on a selected character or item, though the player character and the targeted character may both be in motion</li><li>to enclose (a waterway) with a lock</li></ul>