Phrase guide
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.
No pronunciation record was provided for this word.
noun
A cover whose members are all open sets.
Definition source: English Wiktionary via Wiktextract
Topics: mathematics, sciences, topology
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
History
No etymology was provided for this word.
