open set

ˈəʊpən sɛt

Definition

Definition of open set - Reverso English Dictionary

Noun

mathematics

TECH.

set where each point has a neighborhood fully inside it

TECH.

An open set contains all its interior points.

topological space

TECH.

member of a topology in topological space

TECH.

Each open set is part of the topology.

member

space

topology

Add a suggestion |

Feedback:

Expressions with open

open to

adj.

not closed or restricted allowing access

The garden is open to the public.

open up

start operating or functioning

The shop will open up at 9 AM.

crack open

open something by breaking or splitting it

He had to crack open the coconut with a sharp rock..

open out

unfold or spread out something

She helped to open out the map on the table..

keep one's eyes open

stay alert and notice what is happening around you

You should keep your eyes open when walking at night.

open its doors

allow people to enter

The museum will open its doors to the public next week.

Expressions with set

set up

prepare something for use or operation

They set up the equipment for the concert.

all set

adj.

ready and prepared for an activity

We are all set for the trip.

set down

allow passengers to leave a vehicle

The bus set down passengers at the station.

set foot

enter a place, often with emphasis

She never set foot in that house again.

set back the clock

move a clock's time to an earlier hour

Remember to set back the clock before you go to bed.

set fire to

cause something to start burning

The vandals set fire to the abandoned building.

set free

allow someone or something to be free

They set free the captured birds.

set of pipes

collection of tubes or pipes

The plumber brought a set of pipes to fix the leak.

set off

leave on a journey or trip

We set off early in the morning.

set off fireworks

ignite fireworks to create a display

We set off fireworks to celebrate the New Year.

Terms with open set included in their meaning

💡 A powerful way to uncover related words, idioms, and expressions linked by the same idea — and explore meaning beyond exact word matches.

combination

lock code

set of numbers or letters used to open a lock

firm offer

legal

binding business proposal that stays open for a set period

free market

business

economic system where prices are set by open competition

interior

mathematics

largest open set contained entirely within a given set

continuous function

topology

function where the inverse image of any open set is open

sandbox game

video games

video game with open-ended play and no set goals

time lock

security

set a lock to open at a specific time

topological space

math theory

set equipped with rules for open collections, supporting continuity and limits

Examples of open set in a sentence

Open set concepts are key in topology.
An open set can be a union of other open sets.
In topology, an open set does not include its boundary.

View all translations of open set

✨Click below to see the appropriate translations facing each meaning.

French:ensemble ouvert, élément ouvert, ...
German:offene Menge, ...
Italian:insieme aperto, set aperto, ...
Spanish:conjunto abierto, elemento topológico, ...
Portuguese:conjunto aberto, ...
Chinese:开集, 拓扑开集, ...
Japanese:開集合, ...
Arabic:مَجْمُوعَة مُفْتُوحَة, ...
Hebrew:קְבוּצָה פְּתוּחָה, קְבוּצָה טוֹפּוֹלוֹגִית, ...
Russian:открытое множество, ...
Ukrainian:відкрита множина, відкрита множина в топології, ...
Hindi:खुला समुच्चय, खुला सेट, ...
Bengali:ওপেন সেট, টপোলজির সদস্য, ...
Catalan:conjunt obert, element obert, ...
Czech:otevřená množina, ...
Danish:åben mængde, ...
Dutch:open verzameling, ...
Greek:ανοικτό σύνολο, τοπολογικό σύνολο, ...
Hungarian:nyílt halmaz, ...
Khmer:សំណុំបើក, សំណុំបើកចំហ, ...
Korean:오픈셋, 오픈 셋, ...
Persian:مجموعه باز, مجموعه گشوده, ...
Polish:zbiór otwarty, ...
Portuguese (BR):conjunto aberto, ...
Romanian:mulțime deschisă, ...
Swedish:öppen mängd, öppet set, ...
Thai:เซตเปิด, ...
Turkish:açık küme, topoloji üyesi, ...
Vietnamese:tập mở, tập không đóng, ...

Discover how Reverso redefines the dictionary

Go beyond “simple words”

100,000 expressions & idioms Understand any expression you come across: from corporate jargon like 💬 touch base or ↩️ circle back to everyday expressions such as 🌊 out of the blue or 🦆 lame duck, as well as idioms like 🍲 spill the beans and 🐎 hold your horses.

40,000 images When you search for a concrete noun or object, images help you grasp the meaning at a glance. Try searching for 🧵 puppytooth, 🎠 merry-go-round, ⚜️ fleur-de-lys, or 💤 bunk bed.

Informal language & slang Everyday conversations are packed with informal expressions and slang. Meanings are clearly tagged, so you'll always know when a word is casual. Look up hangry (😋 hungry + 😡 angry), 😎 rizz, 🕹️ noob, or 🔑 low-key.

Abbreviations & acronyms Quickly decode modern abbreviations and acronyms. Go from IDK to OMG in seconds and stay up to date with popular abbreviations such as 🐐 GOAT, 📜 tl;dr, 👀 POV, or 🖥️ AFK.

Regional usage (US / UK) Reverso highlights regional differences between American and British English. You’ll never have to wonder where a word is commonly used: try lift vs. elevator, courgette vs. zucchini, or popular British slang like dodgy or banter. What’s more, when you search for 'color', you’ll immediately see its British counterpart, 'colour'.

Get more than a simple definition

Translations for each meaning View translations alongside each meaning to see how a word is translated in each context. Simply toggle translations ON and choose among 25+ languages. You can also display the translation of definitions or examples into your native language to deepen your understanding.

Synonyms & related words by meaning View synonyms and related words for each meaning, not just for the word as a whole. This helps you choose the most accurate word for your context. Click the

icon to discover related terms: analogies, antonyms, common collocates, words with same roots, umbrella terms… Try with happening or hunch.

Multiple examples for every meaning Each meaning comes with three real-life examples to show you how the word is used in different contexts. Click the

icon next to the first example to see two additional options and learn to use new vocabulary naturally.

Go from understanding to mastery

Save words for later review Click the

icon to save words you want to revisit. You can also save a specific meaning by clicking on the

icon next to it. For example, you might want to save the word “table” as a verb, which means “to postpone”.

Practice with personalized flashcards Reverso automatically transforms your searches and saved words into personalized flashcards and quizzes, featuring high-quality audio and usage examples. This helps you transform terms you only recognize into words you actually use confidently.

Learn with Netflix, YouTube, and your favorite texts With Reverso Chrome extension, transform movies, TV shows, articles, or song lyrics into an interactive lesson. Look up words and expressions in one click on any website and learn with your favorite content.

Definition of open set - Reverso English Dictionary

Noun

Expressions with open

Expressions with set

Terms related to open set

Terms with open set included in their meaning

Examples of open set in a sentence

View all translations of open set

Discover how Reverso redefines the dictionary

Go beyond “simple words”

Get more than a simple definition

Go from understanding to mastery