noun in·sect \ ˈin-ˌsekt \
|Updated on: 15 Aug 2018

Definition of insect

1 a : any of numerous small invertebrate animals (such as spiders or centipedes) that are more or less obviously segmented not used technically
b : 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
2 : a trivial or contemptible person



Examples of insect in a Sentence

  1. a swarm of flying insects

  2. the magazine's editor in chief was notorious for treating staffers as insects, often not even bothering to learn their names

Recent Examples of insect from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'insect.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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.

Illustration of insect

illustration of insect

Origin and Etymology of insect

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

INSECT Defined for English Language Learners


Definition of insect for English Language Learners

  • : a small animal that has six legs and a body formed of three parts and that may have wings

  • : an animal (such as a spider) that is similar to an insect

INSECT Defined for Kids


noun in·sect \ ˈin-ˌsekt \

Definition of insect for Students

1 : any of a group of small and often winged animals that are arthropods having six jointed legs and a body formed of a head, thorax, and abdomen
  • Flies, bees, and lice are true insects.
2 : an animal (as a spider or a centipede) similar to the true insects
Hint: This meaning is not scientifically accurate but may be encountered in common everyday use.

History for insect

The distinct parts into which insects’ bodies are divided—head, thorax, and abdomen—inspired the Greek name used for them by the philosopher Aristotle: entomon, the “notched” or “segmented” animal. (Entomon is a noun derived from the verb entemnein, “to cut up” or “to cut into.”) The Romans used insectum, a literal translation of Greek entomon, as their name for the creatures, and this Latin word has provided us with the ordinary English word for insects.

Medical Dictionary


noun in·sect \ ˈin-ˌsekt \

medical Definition of insect

: any arthropod of the class Insecta



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fullness to the point of excess

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