sporadic (adj.) Look up sporadic at Dictionary.com
1680s, from Medieval Latin sporadicus "scattered," from Greek sporadikos "scattered," from sporas (genitive sporados) "scattered, dispersed," from spora "a sowing" (see spore). Originally a medical term, "occurring in scattered instances;" the meaning "happening at intervals" is first recorded 1847. Related: Sporadical (1650s); sporadically.