Standard Lemma guide

retroactivity

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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  • CMU ARPABET: R EH2 T R OW0 AE0 K T IH1 V IH0 T IY0 Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.

1

noun

Meaning 1

The state or characteristic of being retroactive.

Definition source: English Wiktionary via Wiktextract

Usage: uncountable, usually

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

The application of a law to events that took place before it was made.

Definition source: English Wiktionary via Wiktextract

Usage: uncountable, usually

Topics: law

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

History

Etymology

Etymology tree English retroactive Proto-Indo-European *-teh2 Proto-Indo-European *-ts Proto-Indo-European *-teh2ts Latin -itāsder. Old French -itebor. Middle English -ite English -ity English retroactivity From retroactive + -ity.

Across languages

Translations

5 source translations are retained for this English entry.

  • Irish: aisghníomhaíocht — the state or characteristic of being retroactive
  • Swedish: retroaktivitet — the state or characteristic of being retroactive
  • Czech: retroaktivita — law: the application of a law to events that took place before it was made
  • Irish: cúlghabhálacht — law: the application of a law to events that took place before it was made
  • Swedish: retroaktivitet — law: the application of a law to events that took place before it was made