Occuring occasionally, singly or in irregular or random instances.
1) Sporadic cases of the disease were reported.
2) Sporadic loud voices kept startling everyone in the neighbourhood.
Medieval Latin sporadicus, from Greek sporadikos, from sporadēn hereand there, from sporad-,
sporasscattred; akin to Greek speirein which means 'to sow'.
casual, choppy, catchy, erratic, spotty, unsteady
constant, continuous, periodic.