Insect Definition & Meaning - Merriam-Webster

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

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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 During the 2017 eclipse, a study using radar to detect bird and insect movement in the air showed a flush of activity during totality, Dunn said. Karl Schneider, The Indianapolis Star, 18 Mar. 2024 Pests and Problems Aphids are the most common insect gardeners encounter on Easter lilies, although spider mites, thrips, and scale are occasional visitors. Derek Carwood, Better Homes & Gardens, 18 Mar. 2024 His delight in learning there, for example, that flowers evolved to bloom in brilliant hues because insects had color vision—and not the other way around—is palpable. Julie Belcove, Robb Report, 16 Mar. 2024 Boxwoods that perished or were severely damaged were most likely weakened ahead of the freeze by insect damage. Chris McKeown, The Enquirer, 16 Mar. 2024 In coming decades, climate change will make red pine and other Northwoods trees increasingly vulnerable to destructive combinations of longer, warmer summers and less extremely cold winters, as well as droughts, windstorms, wildfires and insect infestations. Smithsonian Magazine, 15 Mar. 2024 The good news is that food is plentiful with insect hatches and baitfish spawns in full swing. Shaye Baker, Field & Stream, 6 Mar. 2024 It’s amplified in the tree boughs and joined by gentle insect songs. Ryan Ballogg, Miami Herald, 29 Feb. 2024 Food in nature: The hummingbird's diet includes nectar from flowers, red flowers being their favorite, and small insects. Chad Murphy, The Enquirer, 27 Feb. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'insect.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

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

Dictionary Entries Near insect

Cite this Entry

“Insect.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/insect. Accessed 26 Mar. 2024.

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

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