Standard Lemma guide

isotherm

noun · 2 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.

  • UK: /ˈaɪ.səʊˌθɜː(ɹ)m/
  • Southern-England: Recorded audio is listed in the source snapshot.

1

noun

Meaning 1

A line on a graph or chart, such as a weather map, along which all the points have the same temperature.

Definition source: English Wiktionary via Wiktextract

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: thermoisopleth

Antonyms: none provided

2

noun

Meaning 2

(meteorology) an isogram connecting points having the same temperature at a given time

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: isogram, isopleth, isarithm

History

Etymology

From the French isotherme (“of equal temperature”, adjective), itself from Ancient Greek ἴσος (ísos, “equal”) + θέρμη (thérmē, “warmth”). By surface analysis, iso- + -therm.

Across languages

Translations

19 source translations are retained for this English entry.

  • Chinese Mandarin: 等溫線 /等温线 (děngwēnxiàn) — line representing equal temperature
  • Czech: izoterma — line representing equal temperature
  • Dutch: isotherm — line representing equal temperature
  • Esperanto: izotermo — line representing equal temperature
  • Estonian: isoterm — line representing equal temperature
  • Estonian: samasoojusjoon — line representing equal temperature
  • Finnish: isotermi — line representing equal temperature
  • Finnish: lämpökäyrä — line representing equal temperature
  • German: Isotherme — line representing equal temperature
  • Greek: ισόθερμος (isóthermos) — line representing equal temperature
  • Ido: izotermo — line representing equal temperature
  • Irish: isiteirm — line representing equal temperature
  • Italian: isoterma — line representing equal temperature
  • Latvian: izoterma — line representing equal temperature
  • Lithuanian: izotermė — line representing equal temperature
  • Polish: izoterma — line representing equal temperature
  • Portuguese: isoterma — line representing equal temperature
  • Russian: изоте́рма (izotérma) — line representing equal temperature
  • Tagalog: kakaintan — line representing equal temperature