plural of fille fatale

Any of several fireflies, of the genus Photuris, that mimic the mating flashes of other species in order to predate the attracted males.

plural of femme fatale firefly

A very rare autosomal-dominant inherited prion disease of the brain, in which progressively worsening insomnia leads to hallucinations and delirium.

(computing) An error that occurs when an operating system halts, because it has reached a condition where it can no longer operate safely.

plural of fatal system error