ignis fatuus
[noun]
Synonyms: delusion, hallucination, illusion, mirage, phantasm

[TahlilGaran] English Synonym Dictionary ▲

ignis fatuus noun phr. [,ɪgnɪs 'fatjʊǝs] Pl. ignes fatui [,ɪgni:z 'fatjʊʌɪ, ,ɪgneɪz 'fatjʊi:]. M16.
[mod. Latin = foolish fire, so called from its erratic flitting from place to place.]
1. A phosphorescent light seen hovering or floating over marshy ground, perh. due to the combustion of methane; a will-o'-the-wisp. M16.

2. fig. A delusive guiding principle, hope, or aim. L16.
■ Y. Menuhin I don't fear indolence, confident..that the gift is not an ignis fatuus, there one minute and gone the next.

[TahlilGaran] English Dictionary ▲