What is "sporadic disease"

Sporadic \Spo*rad"ic\ (-r[a^]d"[i^]k), a. [Gr. ? scattered, fr. ?, ?, scattered, fr. ? to sow seed, to scatter like seed: cf. F. sporadique. See Spore.] Occurring singly, or apart from other things of the same kind, or in scattered instances; separate; single; as, a sporadic fireball; a sporadic case of disease; a sporadic example of a flower.

Sporadic disease (Med.), a disease which occurs in single and scattered cases. See the Note under Endemic, a.