Standard Lemma guide

lunacy

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.

  • UK: /ˈluː.nə.si/
  • UK: /ˈljuː.nə.si/
  • US: /ˈluː.nə.si/
  • US: Recorded audio is listed in the source snapshot.
  • Australia: Recorded audio is listed in the source snapshot.
  • CMU ARPABET: L UW1 N AH0 S IY0 Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.

1

noun

Meaning 1

The state of being mad, insanity

A cyclical mental disease, apparently linked to the lunar phases.

Definition source: English Wiktionary via Wiktextract

Usage: countable, uncountable

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

The state of being mad, insanity

Insanity implying legal irresponsibility.

Definition source: English Wiktionary via Wiktextract

Usage: countable, uncountable

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

3

noun

Meaning 3

Something deeply misguided.

Definition source: English Wiktionary via Wiktextract

Usage: countable, uncountable

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

4

noun

Meaning 4

foolish or senseless behavior

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: folly, foolery, tomfoolery, craziness, indulgence

Antonyms: none provided

Broader terms: play, frolic, romp, gambol, caper

Narrower terms: meshugaas, mishegaas, mishegoss, buffoonery, clowning, japery, frivolity, harlequinade, prank

5

noun

Meaning 5

obsolete terms for legal insanity

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: madness, insaneness

Antonyms: none provided

Broader terms: insanity

History

Etymology

From lun(atic) + -acy.

Across languages

Translations

36 source translations are retained for this English entry.

  • Bulgarian: лудост (ludost) — state of being mad
  • Chinese Mandarin: 精神病 (jīngshénbìng) — state of being mad
  • Chinese Mandarin: 神經病 /神经病 (shénjīngbìng) — state of being mad
  • Danish: galskab — state of being mad
  • Dutch: gekheid — state of being mad
  • Dutch: krankzinnigheid — state of being mad
  • Dutch: waanzin — state of being mad
  • Finnish: hulluus — state of being mad
  • French: folie — state of being mad
  • German: Verrücktheit — state of being mad
  • German: Wahnsinn — state of being mad
  • Irish: gealtachas — state of being mad
  • Italian: pazzia — state of being mad
  • Manx: ard-ommidjys — state of being mad
  • Marathi: वेड (veḍ) — state of being mad
  • Norwegian: galskap — state of being mad
  • Old English: mōnaþsēocnes — state of being mad
  • Plautdietsch: Wonsenn — state of being mad
  • Polish: obłęd — state of being mad
  • Polish: niepoczytalność — state of being mad
  • Russian: безу́мие (bezúmije) — state of being mad
  • Russian: невменя́емость (nevmenjájemostʹ) — state of being mad
  • Russian: помеша́тельство (pomešátelʹstvo) — state of being mad
  • Russian: сумасше́ствие (sumasšéstvije) — state of being mad
  • Russian: умопомеша́тельство (umopomešátelʹstvo) — state of being mad
  • Spanish: locura — state of being mad
  • Spanish: lunatismo — state of being mad
  • Turkish: cinnet — state of being mad
  • Turkish: çılgınlık — state of being mad
  • Turkish: delilik — state of being mad
  • Ottoman Turkish: جنت (cinnet) — state of being mad
  • Ottoman Turkish: مجنونلق (mecnunluk) — state of being mad
  • Dutch: maanziekte — cyclical mental disease, apparently linked to the lunar phases
  • Dutch: gekheid — something deeply misguided
  • Dutch: waanzin — something deeply misguided
  • Finnish: hulluus — something deeply misguided
Real reading context

lunacy in complete knowledge articles