interlock

American  

[in-ter-lok, in-ter-lok, in-ter-lok] / ˌɪn tərˈlɒk, ˈɪn tərˌlɒk, ˈɪn tərˌlɒk /

verb (used without object)

• interlocks,
  present (3rd person singular)
• interlocked,
  past participle,  past
• interlocking
  present participle

1. to fit into each other, as parts of machinery, so that all action is synchronized.

2. to interweave or interlace, one with another.

   The branches of the trees interlock to form a natural archway.

3. Railroads. (of switches, signals, etc.) to operate together in a prearranged order.

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verb (used with object)

• interlocks,
  present (3rd person singular)
• interlocked,
  past participle,  past
• interlocking
  present participle

1. to lock one with another.

2. to fit (parts) together to ensure coordinated action.

3. Railroads. to arrange (switches, signals, etc.) to effect a predetermined sequence of movement.

noun

1. the fact or condition of interlocking or of being interlocked.

2. the existence or an instance of an interlocking directorate.

3. a device for preventing a mechanism from being set in motion when another mechanism is in such a position that the two operating simultaneously might produce undesirable results.

4. Also called ignition interlock.  a device or system that prevents an automotive engine from starting until the seat belt for any occupied front seat is fastened.

5. a stretch fabric made with a circular knitting machine having two alternating sets of long and short needles.

6. Movies. a device for synchronizing the action of a camera and sound recorder.

interlock British  

verb

1. to join or be joined firmly, as by a mutual interconnection of parts

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noun

1. the act of interlocking or the state of being interlocked

2. a device, esp one operated electromechanically, used in a logic circuit or electrical safety system to prevent an activity being initiated unless preceded by certain events

3. a closely knitted fabric

adjective

1. (of fabric) closely knitted

Other Word Forms

Derived Forms

• interlocker
  noun
• uninterlocked
  adjective

Inflected Forms

Participles

• interlocking
  present
• interlocked
  past

Conjugated Forms

Present

• interlock
  simple
• interlocks
  simple
• have interlocked
  perfect
• has interlocked
  perfect
• am interlocking
  progressive
• are interlocking
  progressive
• is interlocking
  progressive
• have been interlocking
  perfect progressive
• has been interlocking
  perfect progressive

Past

• interlocked
  simple
• had interlocked
  perfect
• was interlocking
  progressive
• were interlocking
  progressive
• had been interlocking
  perfect progressive

Future

• will interlock
  simple
• will have interlocked
  perfect
• will be interlocking
  progressive
• will have been interlocking
  perfect progressive

Etymology

Origin of interlock

First recorded in 1625–35; inter- + lock ¹

Explanation

When things interlock with each other, they fit or work together. When a bicycle is properly built, all of its separate parts interlock. The parts of a machine have to interlock for it to work well: gears must interlock with each other, for example. You can also interlock fingers with another person, holding hands so that they're laced together. This verb, dating from the 17th century, combines inter-, "between" and lock, "to close or to lock," from an Old English root.

Example Sentences

See Examples For:

interlock interlocks interlocked interlocking

Maerl beds may closely resemble corals but they are in fact thousands of pieces of free-living calcified seaweed that can interlock to create a carpet brimming with life.

From BBC ● Jul. 31, 2026

By designing particles that interlock in a similar way to staples, they hope to create materials that are strong, adaptable, and potentially recyclable.

From Science Daily ● Jun. 15, 2026

Also like MBS and CDS, new financial assets have begun to interlock in odd, hard-to-understand ways with traditional financial products.

From Barron's ● Feb. 24, 2026

The ends do meet and interlock in their own way, but the process is messy and imperfect — it feels honest.

From Los Angeles Times ● Nov. 7, 2023

We had—or rather Gretchen had—found a way to break down the communication barrier and interlock with another species.

From This Side of Wild by Gary Paulsen

Park’s directorial vernacular, which pairs brutal subject matter with black comedy, interlocks neatly with Nguyen’s satirical style.

From Los Angeles Times ● Apr. 11, 2024

The subfloor needs to be in the same plane so the LVP interlocks and stays locked when you walk on it.

From Seattle Times ● Mar. 4, 2024

Japanese Brazilian Yutaka Toyota interlocks arcs of shiny metal whose curved surfaces serve as sorts of funhouse mirrors.

From Washington Post ● Nov. 25, 2022

What makes evaluating Apple’s potential overreach so complicated is that every criticism you can levy at the company interlocks.

From The Verge ● Jun. 21, 2019

She interlocks her hand with mine as we enter the treatment salon.

From "The Belles" by Dhonielle Clayton

The school alarm would pierce the air and teachers would instruct us to slide from our chairs, crouch under our desks facing the floor, and place our hands, fingers interlocked, over our necks.

From The Wall Street Journal ● Mar. 26, 2026

That thread is exquisitely interlocked with a sensitive, sharp portrait of the interiority of someone searching for agency while in the throes of dementia.

From Los Angeles Times ● Jun. 27, 2025

There were no fixed guards preventing access to the blades from the underside and there were not any interlocked guards which would stop the rotating blades.

From BBC ● Aug. 13, 2024

Before police cleared the area around Hamilton Hall on April 30, 30 or so students interlocked arms outside the building in a human barricade to protect the protesters inside.

From Slate ● Jun. 4, 2024

Then she tapped her nose with her interlocked fingers.

From "The London Eye Mystery" by Siobhan Dowd

Also on Heritage Crafts' red list is dry stone walling - an ancient method of building structures from interlocking stones without using any mortar.

From BBC ● Aug. 1, 2026

Nuances of the interlocking set of official inflation measures—the Labor Department’s consumer- and producer-price indexes, both of which feed into the Commerce Department’s PCE reading—usually attract attention only from technical experts.

From The Wall Street Journal ● Mar. 18, 2026

Around 95 million years ago, the Spinosaurus -- a massive beast with a blade-shaped head crest and interlocking teeth -- roamed the African continent.

From Barron's ● Feb. 27, 2026

The skull also reveals tightly interlocking upper and lower teeth that formed an effective trap for slippery prey.

From Science Daily ● Feb. 23, 2026

It was so beautiful, my heart leaped—metal wings constructed from thousands of interlocking bronze feathers.

From "The Battle of the Labyrinth" by Rick Riordan

Related Words

• interlace
• interlink
• intertwine