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ignis fatuus(ĭg`nĭs făch`o͞oəs): see will-o'-the-wispwill-o'-the-wisp,
phenomenon known also as ignis fatuus and jack-o'-lantern. It is seen at night as a pale, flickering light over marshland. There is no generally accepted explanation for it; it may result from the spontaneous ignition of gases (e.g.
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