Standard Lemma guide

reactant

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

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1

noun

Meaning 1

Any of the participants present at the start of a chemical reaction, specifically one that is consumed during the reaction.

Definition source: English Wiktionary via Wiktextract

Topics: chemistry, natural-sciences, physical-sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: reagent

2

noun

Meaning 2

a chemical substance that is present at the start of a chemical reaction

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: chemical, chemical substance

History

Etymology

Etymology tree English react Proto-Indo-European *-onts Latin -ns Latin -āns Old French -antbor. Proto-Indo-European *-onts Proto-Germanic *-ndz Proto-West Germanic *-andī Old English -ende Middle English -ant English -ant English reactant From react + -ant.

Across languages

Translations

24 source translations are retained for this English entry.

  • Bulgarian: реагент (reagent) — participant at the start of a chemical reaction
  • Chinese Mandarin: 反應物 /反应物 (fǎnyìngwù) — participant at the start of a chemical reaction
  • Finnish: reaktantti — participant at the start of a chemical reaction
  • Finnish: lähtöaine — participant at the start of a chemical reaction
  • French: réactif — participant at the start of a chemical reaction
  • German: Reaktant — participant at the start of a chemical reaction
  • German: Edukt — participant at the start of a chemical reaction
  • German: Reagenz — participant at the start of a chemical reaction
  • Hebrew: מֵגִיב (megív) — participant at the start of a chemical reaction
  • Hindi: अभिकारक (abhikārak) — participant at the start of a chemical reaction
  • Japanese: 試薬 (shiyaku) — participant at the start of a chemical reaction
  • Japanese: 試剤 (shizai) — participant at the start of a chemical reaction
  • Khmer: ប្រតិករ (praʼtekɑɑ) — participant at the start of a chemical reaction
  • Māori: pūmatū hohe — participant at the start of a chemical reaction
  • Māori: pūmatūhope — participant at the start of a chemical reaction
  • Norwegian Bokmål: reaktant — participant at the start of a chemical reaction
  • Norwegian Nynorsk: reaktant — participant at the start of a chemical reaction
  • Romanian: reactiv — participant at the start of a chemical reaction
  • Romanian: reactant — participant at the start of a chemical reaction
  • Russian: реаге́нт (reagént) — participant at the start of a chemical reaction
  • Russian: реакти́в (reaktív) — participant at the start of a chemical reaction
  • Serbo-Croatian: reaktant — participant at the start of a chemical reaction
  • Spanish: reactivo — participant at the start of a chemical reaction
  • Tagalog: kabalibilos — participant at the start of a chemical reaction