English Reference

Word

comet

US/ˈkɑmət/

UK/kˈɒmɪt/

Definitions

01astronomy

B2 · Science

n. a ball of ice and dust in space that has a long tail of light when it moves near the sun.

n. a small solar system body that orbits the sun and, when close enough, displays a visible atmosphere or tail due to the effects of solar radiation.

“The comet was visible in the night sky for several weeks as it passed the earth.”

“Halley's Comet is perhaps the most famous periodic visitor to our inner solar system, returning to the vicinity of Earth every seventy-five years.”

Usage

Often used with the verbs 'orbit', 'appear', or 'pass'.

02computing

C2 · Computing

n. a way for a web server to send information to a browser immediately without waiting for a request.

n. a web application model where a long-held HTTP request allows a server to push data to a client browser.

“The developer used a comet approach to make the chat app update in real time.”

“Before the widespread adoption of WebSockets, Comet was a common technique for achieving low-latency communication between the server and the browser.”

Technical

Usage

Usually treated as an uncountable technical concept or a specific architectural pattern.

Synonyms

server pushHTTP streaming

Real-World Examples

“As sunlight heated the comet's icy surface, gas and dust escaped and created a bright cloud (or coma) around its core.”
ScienceDaily · 9 Sept 2026
“It would reach Halley's Comet in 2060, around a year before its next perihelion and safely outside Mars' orbit.”
Phys.org · 8 Sept 2026

Etymology

From Middle English comete, partly from Old English comēta and partly from Old French comete, both from Latin comētēs, from Ancient Greek κομήτης (komḗtēs, “longhaired”), short for ἀστὴρ κομήτης ([astēr] komētēs, "longhaired [star])" and referring to the tail of a comet, from κόμη (kómē, “hair”). Compare English faxed star and Latin crīnīta stēlla (“comet”, literally “(long) haired star”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Related words

Domains

AstronomyProgramming

This entry

Level
B2 · Upper Intermediate
Frequency
Frequent
Updated

Scan code

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English Reference