monomaniac

• (Received Pronunciation) IPA^(key): /ˌmɒnəʊˈmeɪnɪæk/
• (US) IPA^(key): /ˌmɑnoʊˈmeɪnɪæk/
• Rhymes: -eɪniæk

monomaniac (plural monomaniacs)

1. A person who is obsessed with a single thing, to the exclusion of other concerns.
   • 1859, George Meredith, chapter 15, in The Ordeal of Richard Feverel. A History of Father and Son. […], volume (please specify |volume=I to III), London: Chapman and Hall, →OCLC:

     To talk nonsense, or poetry, or the dash between the two, in a tone of profound sincerity, and to enunciate solemn discordances with received opinion so seriously as to convey the impression of a spiritual insight, is the peculiar gift by which monomaniacs, having first persuaded themselves, contrive to influence their neighbours, and through them to make conquest of a good half of the world, for good or for ill.

   • 1873, Horatio Alger, Bound to Rise, Ch. X

     Harry knew now that the old man was crazy, or at least a monomaniac, and, though he seemed harmless enough, it was of course possible that he might be dangerous.

   • 1890, Arthur Conan Doyle, The Firm of Girdlestone, Ch. 44

     He had never yet been able to determine whether the old man was a consummate hypocrite or a religious monomaniac.

   Synonym: fanatic

monomaniac

1. Focused on one thing above all others.
   • 1851 November 14, Herman Melville, chapter 133, in Moby-Dick; or, The Whale, 1st American edition, New York, N.Y.: Harper & Brothers; London: Richard Bentley, →OCLC:

     ...then it was that monomaniac Ahab, furious with this tantalizing vicinity of his foe, which placed him all alive and helpless in the very jaws he hated; frenzied with all this, he seized the long bone with his naked hands, and wildly strove to wrench it from its gripe.

• monomania
• monomaniacal
• monomaniacally

From French monomaniaque.

monomaniac m or n (feminine singular monomaniacă, masculine plural monomaniaci, feminine and neuter plural monomaniace)

1. monomaniac