insect

noun

in·​sect ˈin-ˌsekt How to pronounce insect (audio)
1
a
: any of a class (Insecta) of arthropods (such as bugs or bees) with well-defined head, thorax, and abdomen, only three pairs of legs, and typically one or two pairs of wings
b
: any of numerous small invertebrate animals (such as spiders or centipedes) that are more or less obviously segmented
not used technically
2
: a trivial or contemptible person
insect adjective

Illustration of insect

Illustration of insect
  • 1 labial palpus
  • 2 maxillary palpus
  • 3 simple eye
  • 4 antenna
  • 5 compound eye
  • 6 prothorax
  • 7 tympanum
  • 8 wing
  • 9 ovipositor
  • 10 spiracles
  • 11 abdomen
  • 12 metathorax
  • 13 mesothorax

Did you know?

The bodies of insects have segments, or divisions, so they appear to have a series of notches cut into them. This led the Greek philosopher Aristotle to give insects the name entomon “a thing cut into.” Entomon comes from the prefix en- “in,” combined with the verb temnein “to cut.” Later, when the Romans wanted a word for this kind of creature, they did not simply borrow the Greek word. Instead they translated it with the Latin word insectum, from the verb insecare “to cut into.” Insectum was borrowed into English as insect.

Examples of insect in a Sentence

a swarm of flying insects the magazine's editor in chief was notorious for treating staffers as insects, often not even bothering to learn their names
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Introduce predatory insects like parasitic wasps that prey on caterpillars and welcome birds in the garden. Mary Marlowe Leverette, Southern Living, 14 Aug. 2025 Apart from the insects crawling on Olivia’s hands, cows in the slaughterhouse inhabit the film’s world alongside Olivia. Jason Liwag, Variety, 14 Aug. 2025 Mosquitoes and other insects swarm around, temperatures fluctuate from sweltering Florida heat to bone-shaking cold from industrial air conditioners, and access to medical attention is limited, according to Bichara. Peter Charalambous, ABC News, 14 Aug. 2025 In addition to their irritating, itchy bites, the insects can carry diseases like West Nile, which has been detected in Milwaukee County this year. Madeline Heim, jsonline.com, 13 Aug. 2025 See All Example Sentences for insect

Word History

Etymology

Latin insectum, from neuter of insectus, past participle of insecare to cut into, from in- + secare to cut — more at saw

First Known Use

1601, in the meaning defined at sense 1b

Time Traveler
The first known use of insect was in 1601

Browse Nearby Words

Cite this Entry

“Insect.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/insect. Accessed 21 Aug. 2025.

Kids Definition

insect

noun
in·​sect ˈin-ˌsekt How to pronounce insect (audio)
1
: any of numerous small invertebrate animals (as spiders or centipedes) that are more or less obviously made up of segments
not used technically
2
: any of a class of arthropods (as butterflies, true bugs, two-winged flies, bees, and grasshoppers) with the body clearly divided into a head, thorax, and abdomen, with three pairs of jointed legs, and usually with one or two pairs of wings
Etymology

from Latin insectum "insect," derived from insecare "to cut into," from in- "in" and secare "to cut" — related to dissect, section

Word Origin
The bodies of insects have segments, or divisions. Thus they seem to have a series of notches cut into them. This appearance led the Greek philosopher Aristotle to give insects the name entomon "a thing cut into." Entomon comes from the prefix en- "in," combined with the verb temnein "to cut." Later, when the Romans wanted a word for this kind of creature, they did not simply borrow the Greek word. Instead they translated it into the Latin word insectum, from the verb insecare "to cut into." Insectum was borrowed into English as insect.

Medical Definition

insect

noun
in·​sect ˈin-ˌsekt How to pronounce insect (audio)
: any arthropod of the class Insecta
insect adjective

More from Merriam-Webster on insect

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