latch

American  

[lach] / lætʃ /

noun

1. a device for holding a door, gate, or the like, closed, consisting basically of a bar falling or sliding into a catch, groove, hole, etc.

2. a breastfeeding baby’s attachment or connection to the mother’s breast.

   A good, deep latch is important because it allows the infant to get enough milk.

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verb (used with object)

1. to close or fasten with a latch.

2. to attach (a breastfeeding baby) to the breast.

   You should know how to properly latch your newborn.

verb (used without object)

1. to close tightly so that the latch is secured.

   The door won't latch.

2. (of a breastfeeding baby) to be or become attached to the breast.

   Failure to latch can be the result of poor positioning of the baby.

verb phrase

1. latch onto

   1. to take possession of; obtain; get.

   2. to acquire understanding of; comprehend.

   3. to attach oneself to; join in with.

      The stray dog latched onto the children and wouldn't go home.

2. latch on

   1. to grab or hold on, as to an object or idea, especially tightly or tenaciously.

   2. to include or add in; attach.

      If we latch the tax on, the bill will come to over $100.

latch British  

/ lætʃ /

noun

1. a fastening for a gate or door that consists of a bar that may be slid or lowered into a groove, hole, etc

2. a spring-loaded door lock that can be opened by a key from outside

3. Also called: latch circuit.  electronics a logic circuit that transfers the input states to the output states when signalled, the output thereafter remaining insensitive to changes in input status until signalled again

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verb

1. to fasten, fit, or be fitted with or as if with a latch

Other Word Forms

Derived Forms

• relatch
  verb (used with object)

Etymology

Origin of latch

First recorded before 950; Middle English lacchen, Old English lǣccan “to take hold of, catch, seize”; akin to Greek lázesthai “to take”

Explanation

When you unlock your front door, you open the latch. A latch is a fastener or lock that you open with a key. A latch can usually be opened with a key or by turning a knob or lifting a hook or bar. You can also use the word latch as a verb, like when your mom reminds you to latch the front and back doors before you leave for school in the morning. In some places, the word "latch-key" is used to mean "key." The root of latch is the Germanic word læccan, "to grasp or seize."

Example Sentences

It’s not unprecedented for struggling companies to latch on to the hot trend of the moment — remember the blockchain hype cycle?

From The Wall Street Journal • Apr. 15, 2026

They equipped astrocytes, a common type of brain cell, with a CAR homing device that allows the cells to latch onto specific targets and destroy them.

From Science Daily • Mar. 11, 2026

Semenyo's winner silenced a raucous and rowdy crowd with a real poacher's finish, reacting quickest to latch on to Rayan Ait-Nouri's cross and converting with aplomb.

From BBC • Feb. 28, 2026

Son should have had another assist, pulling it back from the touchline to Bouanga, who this time could not latch on to the opportunity.

From Barron's • Feb. 22, 2026

Miss Honey simply lifted the latch and pushed open the door and went in.

From "Matilda" by Roald Dahl