Definition of ignis fatuus in English:

ignis fatuus

nounignes fatui

  • A will-o'-the-wisp.

    ‘But it's impossible to describe these paintings, also because they hit your soul like burning arrows and recall the sad and reddish dance of the ignis fatuuses.’
    ‘How is the gas of ignis fatui ignited on bogs and meadows?’
    mirage, hallucination, apparition, phantasm, phantom, vision, spectre, fantasy, figment of the imagination, will-o'-the-wisp, trick of the light

Origin

Mid 16th century modern Latin, literally ‘foolish fire’ (because of its erratic movement).

Pronunciation

ignis fatuus

/ˌɪɡnɪs ˈfatjʊəs/