noun · 3 senses · updated from the 2026-07-25 local source snapshot
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
Pronunciation
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.
Received-Pronunciation:/ˈmɛsəʊsfɪə/
Received-Pronunciation:/ˈmiː-/
UK:Recorded audio is listed in the source snapshot.
General-American:/ˈmɛzoʊsfɪɚ/
US:Recorded audio is listed in the source snapshot.
1
noun
Meaning 1
The layer of the Earth's atmosphere that is directly above the stratosphere and directly below the thermosphere.
Definition source: English Wiktionary via Wiktextract