The word for today is…
sporadic (adj) – 1. Occurring at irregular intervals or in isolated or scattered places; having no pattern or order.
2. (Medicine) Not epidemic, endemic, or inherited. Used of a disease or condition.
Source : The Free Dictionary
Etymology : Sporadic describes the distribution of something across space or time that is not frequent enough to fill an area or period, often in scattered instances or isolated outbursts (as in “sporadic applause”). The word comes from Medieval Latin sporadicus, which is itself derived from Greek sporad?n, meaning “here and there.” It is also related to the Greek verb speirein (“to sow”), the ancestor from which we get our word spore (the reproductive cell of a fungus, microorganism, or some plants), hinting at the seeming scattered nature by which such cells distribute and germinate.