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
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
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
Stingless bees in the Peruvian Amazon have become the first insects anywhere in the world to receive legal rights.
—
Aamir Khollam, Interesting Engineering, 30 Dec. 2025
Theories have included static electricity, swarming insects, birds carrying glowing fungus or lightning that ignites swamp gas.
—Katie Hunt, CNN Money, 29 Dec. 2025
Many fungal diseases and troublesome insect eggs can overwinter in soil.
—Mary Marlowe Leverette, Southern Living, 28 Dec. 2025
The Animal Welfare Act’s definition of animal excludes fish, insects, cephalopods, and most mice and rats.
—The Atlantic Science Desk, The Atlantic, 27 Dec. 2025
See All Example Sentences for insect
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.
Aamir Khollam, Interesting Engineering, 30 Dec. 2025
Theories have included static electricity, swarming insects, birds carrying glowing fungus or lightning that ignites swamp gas.
—Katie Hunt, CNN Money, 29 Dec. 2025
Many fungal diseases and troublesome insect eggs can overwinter in soil.
—Mary Marlowe Leverette, Southern Living, 28 Dec. 2025
The Animal Welfare Act’s definition of animal excludes fish, insects, cephalopods, and most mice and rats.
—The Atlantic Science Desk, The Atlantic, 27 Dec. 2025
See All Example Sentences for insect
Cite this Entry
“Insect.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/insect. Accessed 5 Jan. 2026.
Copy CitationKids Definition
insect
noun
in·sect
ˈin-ˌsekt 
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
Love words? Need even more definitions?
Merriam-Webster unabridged
Share