adj · 4 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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Received-Pronunciation:/ˈmuːnstɹʌk/
General-American:/ˈmunˌstɹʌk/
General-American:Recorded audio is listed in the source snapshot.
CMU ARPABET:M UW1 N S T R AH2 K
Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.
1
adj
Meaning 1
Of a person: perverted or insane, originally supposedly due to the influence of the Moon; compare lunatic.
Definition source: English Wiktionary via Wiktextract
Usage: archaic
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: lunatic, moonstricken
Antonyms: none provided
2
adj
Meaning 2
Showing irrational behaviour, especially of a romantic or sentimental nature; in an entranced or distracted state, especially due to being in love.
Definition source: English Wiktionary via Wiktextract
Usage: figuratively
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: moonstricken
Antonyms: none provided
3
adj
Meaning 3
Made physically sick, or (like fish) unsuitable for food, by the supposed effect of moonlight.
Definition source: English Wiktionary via Wiktextract
Usage: regional
Qualifier: obsolete except UK
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
4
adjective satellite
Meaning 4
insane and believed to be affected by the phases of the moon
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: lunatic
Antonyms: none provided
History
Etymology
From moon + struck (adjective), possibly coined by the English poet and polemicist John Milton (1608–1674): see the quotation. Compare Byzantine Greek σεληνόβλητος (selēnóblētos), σεληνόπληκτος (selēnóplēktos), German mondsüchtig, and German Low German maansüchtig, which also refer to being struck by the moon.
Across languages
Translations
11 source translations are retained for this English entry.
Danish:
månesyg
— of a person: crazy or insane, originally supposedly due to the influence of the Moon — see also crazy, insane
Finnish:
kuuhullu
— of a person: crazy or insane, originally supposedly due to the influence of the Moon — see also crazy, insane
French:
lunatique
— of a person: crazy or insane, originally supposedly due to the influence of the Moon — see also crazy, insane
German:
mondsüchtig
— of a person: crazy or insane, originally supposedly due to the influence of the Moon — see also crazy, insane
Italian:
lunatico
— of a person: crazy or insane, originally supposedly due to the influence of the Moon — see also crazy, insane
Latin:
lunaticus
— of a person: crazy or insane, originally supposedly due to the influence of the Moon — see also crazy, insane
Old English:
mōnaþsēoc
— of a person: crazy or insane, originally supposedly due to the influence of the Moon — see also crazy, insane
Portuguese:
lunático
— of a person: crazy or insane, originally supposedly due to the influence of the Moon — see also crazy, insane
Russian:
лунатик
(lunatik)
— of a person: crazy or insane, originally supposedly due to the influence of the Moon — see also crazy, insane
Welsh:
lloerig
— of a person: crazy or insane, originally supposedly due to the influence of the Moon — see also crazy, insane
Finnish:
lääpällään
— showing irrational behaviour, especially of a romantic or sentimental nature; in an entranced or distracted state, especially due to being in love