: 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
insectadjective
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.
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
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Waste Removal Mushrooms are nature’s decomposers that break down old plant material, dead insects, sticks and woody debris, decaying plant roots, and other organic matter.—Lauren Landers, The Spruce, 16 June 2026 Pests and Disease Sap-sucking insects like thrips, spider mites, aphids, and whiteflies can stunt plant growth or cause severe flower and leaf drop.—Mary Marlowe Leverette, Southern Living, 16 June 2026 Pest control experts recommend switching to yellow bug lights, which tend to attract fewer insects than traditional bulbs.—Tiffani Jackson, Fort Worth Star-Telegram, 16 June 2026 Stinging insects have nested in a wall or underground.—Sharon Wu, USA Today, 16 June 2026 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
: 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.