locust

American  

[loh-kuhst] / ˈloʊ kəst /

noun

1. Also called acridid, short-horned grasshopper.  any of several grasshoppers of the family Acrididae, having short antennae and commonly migrating in swarms that strip the vegetation from large areas.

2. any of various cicadas, as the seventeen-year locust.

3. any of several North American trees belonging to the genus Robinia, of the legume family, especially R. pseudoacacia, having pinnate leaves and clusters of fragrant white flowers.

4. the durable wood of this tree.

5. any of various other trees, as the carob and the honey locust.

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locust British  

/ ˈləʊkəst /

noun

1. any of numerous orthopterous insects of the genera Locusta, Melanoplus, etc, such as L. migratoria, of warm and tropical regions of the Old World, which travel in vast swarms, stripping large areas of vegetation See also grasshopper Compare seventeen-year locust

2. Also called: locust tree.   false acacia.  a North American leguminous tree, Robinia pseudoacacia, having prickly branches, hanging clusters of white fragrant flowers, and reddish-brown seed pods

3. the yellowish durable wood of this tree

4. any of several similar trees, such as the honey locust and carob

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Other Word Forms

Derived Forms

• locustlike
  adjective
• locust-like
  adjective

Etymology

Origin of locust

1150–1200; Middle English < Latin locusta grasshopper

Explanation

A locust is a type of grasshopper that goes through a phase of its life when it joins an enormous group of locusts. A swarm of locusts can devastate farm crops and affect food supplies. Locusts aren't a separate species from grasshoppers — instead, locust is what scientists rename a grasshopper that's changed its habitat and behavior dramatically. Locusts arise from specific environmental conditions, usually drought followed by fast plant growth. Normally solitary grasshoppers become gregarious, banding together, and even changing their size and color. Swarms of locusts can fly long distances, landing en masse to devour vegetation. The Latin root of locust, locusta, also means "lobster."

Example Sentences

While chemical pesticides remain the primary control tool, the Global Locust Initiative is working to identify alternatives that are safer for people and the environment.

From Science Daily • Jan. 24, 2026

The U.S. has deployed a BlueHalo Locust laser weapon system that can shoot down drones with $3 of electricity, also known as “directed energy.”

From The Wall Street Journal • Dec. 28, 2025

Police sealed off Locust Walk with barricades and closed part of Walnut Street to traffic.

From New York Times • May 10, 2024

Like the dormant insect, the Locust has reemerged, intent on destroying the world.

From Los Angeles Times • Feb. 27, 2024

The boys used it to jump their bikes to the other side, where they eventually captured the Queen Locust.

From "The Last Last-Day-of-Summer" by Lamar Giles

Related Words

• grasshopper