Definition of moronism in US English:

moronism

noun

  • 1Psychology. The least severe form of mental retardation.

  • 2The state or condition of being a moron; stupidity, ignorance, imbecility.

Origin

Early 20th century; earliest use found in New York Medical Journal. From moron + -ism.

Pronunciation

moronism

/ˈmɔːrɒnɪz(ə)m/