interlock

American  

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

verb (used without object)

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)

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

• interlocker
  noun
• uninterlocked
  adjective

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

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

I’m interested in the scripts on the field and off, and the plotlines that interlock.

From Slate • Jan. 30, 2024

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

How deeply will it interlock the Pac-12 with the sports streaming giants, Apple and Amazon?

From Seattle Times • Aug. 1, 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

Related Words

• interlace
• interlink
• intertwine