Standard Lemma guide

inertia

noun · 5 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.

  • Australian, UK: /ɪnˈɜː.ʃə/
  • Australian, UK: /ɪˈnɜː.ʃə/
  • Southern-England: Recorded audio is listed in the source snapshot.
  • US: /ɪnˈɝ.ʃə/
  • US: /ɪˈnɝ.ʃə/
  • New-Jersey: Recorded audio is listed in the source snapshot.
  • rhymes with -ɜː(ɹ)ʃə
  • CMU ARPABET: IH2 N ER1 SH AH0 Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.

1

noun

Meaning 1

The property of a body that resists any change to its uniform motion; equivalent to its mass.

Definition source: English Wiktionary via Wiktextract

Usage: countable, uncountable

Topics: natural-sciences, physical-sciences, physics

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

In a person, unwillingness to take action.

Definition source: English Wiktionary via Wiktextract

Usage: countable, figuratively, uncountable

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

3

noun

Meaning 3

Lack of activity; sluggishness; said especially of the uterus, when, in labour, its contractions have nearly or wholly ceased.

Definition source: English Wiktionary via Wiktextract

Usage: countable, uncountable

Topics: medicine, sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

4

noun

Meaning 4

a disposition to remain inactive or inert

Definition source: Princeton WordNet 3.0

Examples

  • he had to overcome his inertia and get back to work

Meaning relationships

Synonyms: inactiveness, inactivity

Antonyms: none provided

Broader terms: trait

Narrower terms: languor, lethargy, sluggishness, phlegm, flatness, restfulness, passivity, passiveness, indolence, laziness

5

noun

Meaning 5

(physics) the tendency of a body to maintain its state of rest or uniform motion unless acted upon by an external force

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: mechanical phenomenon

Narrower terms: moment of inertia

History

Etymology

From Latin inertia (“lack of art or skill, inactivity, indolence”), from iners (“unskilled, inactive”), from in- (“without, not”) + ars (“skill, art”). Something close to the modern physics sense was first used in New Latin by Johannes Kepler.

Across languages

Translations

90 source translations are retained for this English entry.

  • Albanian: inerci — in physics
  • Arabic: عَطَالَة (ʕaṭāla) — in physics
  • Azerbaijani: ətalət — in physics
  • Bulgarian: инерция (inercija) — in physics
  • Catalan: inèrcia — in physics
  • Chinese Mandarin: 慣性 /惯性 (guànxìng) — in physics
  • Czech: setrvačnost — in physics
  • Dutch: inertie — in physics
  • Dutch: traagheid — in physics
  • Esperanto: inerteco — in physics
  • Esperanto: inerteca forto — in physics
  • Esperanto: inertforto — in physics
  • Estonian: inerts — in physics
  • Estonian: inertsus — in physics
  • Finnish: hitaus — in physics
  • Finnish: inertia — in physics
  • Finnish: vitka — in physics
  • Finnish: jatkavuus — in physics
  • French: inertie — in physics
  • German: Trägheit — in physics
  • German: Beharrungsvermögen — in physics
  • German: Beharrung — in physics
  • Greek: αδράνεια (adráneia) — in physics
  • Hawaiian: ehuō — in physics
  • Hindi: अक्रियता (akriytā) — in physics
  • Hungarian: tehetetlenség — in physics
  • Irish: táimhe — in physics
  • Italian: inerzia — in physics
  • Japanese: 慣性 (kansei) — in physics
  • Kazakh: инерция (inersiä) — in physics
  • Khmer: និចលភាព (nĭchlôphéap) — in physics
  • Latin: inertia — in physics
  • Latvian: inerce — in physics
  • Malay: inersia — in physics
  • Malayalam: ജഡത്വം (jaḍatvaṁ) — in physics
  • Māori: tūpuku — in physics
  • Norwegian: treghet — in physics
  • Norwegian: treighet — in physics
  • Polish: bezwładność — in physics
  • Polish: inercja — in physics
  • Portuguese: inércia — in physics
  • Romanian: inerție — in physics
  • Russian: ине́рция (inɛ́rcija) — in physics
  • Scottish Gaelic: do-mhùthadh — in physics
  • Spanish: inercia — in physics
  • Swedish: tröghet — in physics
  • Tagalog: tigal — in physics
  • Tamil: சடத்துவம் (caṭattuvam) — in physics
  • Tamil: நிலைமம் (nilaimam) — in physics
  • Telugu: జడత్వము (jaḍatvamu) — in physics
  • Thai: ความเฉื่อย (kwaam-chʉ̀ai) — in physics
  • Turkish: eylemsizlik — in physics
  • Ukrainian: іне́рція (inércija) — in physics
  • Vietnamese: quán tính — in physics
  • Arabic: عَطَالَة (ʕaṭāla) — unwillingness to take action
  • Bulgarian: мудност (mudnost) — unwillingness to take action
  • Bulgarian: вялост (vjalost) — unwillingness to take action
  • Catalan: inèrcia — unwillingness to take action
  • Dutch: daadloosheid — unwillingness to take action
  • Estonian: tegevusetus — unwillingness to take action
  • Estonian: loidus — unwillingness to take action
  • Finnish: vastahakoisuus — unwillingness to take action
  • German: Trägheit — unwillingness to take action
  • German: Schwerfälligkeit — unwillingness to take action
  • German: Unbeweglichkeit — unwillingness to take action
  • Hindi: निष्क्रियता (niṣkriytā) — unwillingness to take action
  • Hungarian: tétlenség — unwillingness to take action
  • Irish: spadántacht — unwillingness to take action
  • Italian: inerzia — unwillingness to take action
  • Japanese: 惰性 (dasei) — unwillingness to take action
  • Latin: inertia — unwillingness to take action
  • Polish: inercja — unwillingness to take action
  • Polish: bezwładność — unwillingness to take action
  • Portuguese: inércia — unwillingness to take action
  • Russian: ине́ртность (inɛ́rtnostʹ) — unwillingness to take action
  • Russian: вя́лость (vjálostʹ) — unwillingness to take action
  • Scottish Gaelic: leisg — unwillingness to take action
  • Scottish Gaelic: do-mhùthadh — unwillingness to take action
  • Spanish: inercia — unwillingness to take action
  • Swedish: tröghet — unwillingness to take action
  • Thai: ความเฉื่อยชา — unwillingness to take action
  • Turkish: atalet — unwillingness to take action
  • Welsh: llesgedd — unwillingness to take action
  • Welsh: syrthni — unwillingness to take action
  • Finnish: velttous — in medicine
  • Finnish: inertia — in medicine
  • German: Reglosigkeit — in medicine
  • German: Schwerfälligkeit — in medicine
  • German: Trägheit — in medicine
  • Māori: whakapahoho — in medicine