noun \ˈläk\

Definition of LOCK

a :  a tuft, tress, or ringlet of hair
b plural :  the hair of the head
:  a cohering bunch (as of wool, cotton, or flax) :  tuft
plural :  dreadlock 2

Origin of LOCK

Middle English lok, from Old English locc; akin to Old High German loc lock, Greek lygos withe, Latin luxus dislocated
First Known Use: before 12th century



Definition of LOCK

a :  a fastening (as for a door) operated by a key or a combination
b :  the mechanism for exploding the charge or cartridge of a firearm
a :  an enclosure (as in a canal) with gates at each end used in raising or lowering boats as they pass from level to level
b :  air lock
a :  a locking or fastening together
b :  an intricate mass of objects impeding each other (as in a traffic jam)
c :  a hold in wrestling secured on one part of the body; broadly :  a controlling hold <his paper … had a lock on a large part of the state — John Corry>
:  one that is assured of success or favorable outcome

Origin of LOCK

Middle English lok, from Old English loc; akin to Old High German loh enclosure and perhaps to Old English locc lock of hair
First Known Use: before 12th century

Other Hardware Terms

adze, auger, awl, chock, ferrule, punch, tang



: to fasten (something) with a lock

: to fasten the door, lid, etc., of (something) with a lock

: to become fastened with a lock

Full Definition of LOCK

transitive verb
a :  to fasten the lock of
b :  to make fast with or as if with a lock <lock up the house>
a :  to fasten in or out or to make secure or inaccessible by or as if by means of locks <locked himself away from the curious world>
b :  to fix in a particular situation or method of operation <a team firmly locked in last place>
a :  to make fast, motionless, or inflexible especially by the interlacing or interlocking of parts <lock wheels> <lock a knee>
b :  to hold in a close embrace
c :  to grapple in combat; also :  to bind closely <administration and students were locked in conflict>
:  to invest (capital) without assurance of easy convertibility into money
:  to move or permit to pass (as a ship) by raising or lowering in a lock
intransitive verb
a :  to become locked
b :  to be capable of being locked
:  to go or pass by means of a lock (as in a canal)
lock·able \ˈlä-kə-bəl\ adjective
lock horns
:  to come into conflict
lock on or lock onto
:  to acquire (as a target or signal) automatically using a sensor (as radar)

Examples of LOCK

  1. They locked the door when they left and unlocked it when they returned.
  2. She locked the bicycle to the railing with a chain.
  3. He forgot to lock the car.
  4. The car locks automatically when you start the engine.
  5. The wheels locked and the car skidded off the road.
  6. They were locked in each other's arms.
  7. She locked her hands around the steering wheel.
  8. The file is locked for editing.

First Known Use of LOCK

14th century


noun    (Concise Encyclopedia)

A cylinder lock's tumbler consists of a series of pins arranged in pairs. The pins are …—© Merriam-Webster Inc.

Mechanical or electronic device for securing a door or receptacle so that it cannot be opened except by a key or a code. The lock originated in the Middle East; the oldest known example was found near Nineveh. Possibly 4,000 years old, it is of the pin tumbler type, otherwise known as an Egyptian lock. The Romans were the first to use metal locks and to make small keys for them. They also invented wards, projections in the keyhole that prevent a key from turning unless it has slots that avoid the projections. Probably the most familiar lock today is the cylinder lock, a pin tumbler lock opened by a flat key with a serrated edge; the serrations raise pins in the cylinder to the proper heights, allowing the cylinder to turn. Also common are the unit lock, housed within a rectangular notch cut into the edge of a door, and the mortise lock, housed in a mortise cut into the door edge, the lock mechanism being covered on both sides. Other types include lever and combination locks. Electronic locks that open with a magnetic card key are popular for banks, hotel rooms, and offices.


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