discontinuous, on-again off-again, spasmodic, seasonal, off-again, cyclical, by snatches, occasional, shifting, periodic, continue, every other, on and off, epochal, alternate, recurrent, coming and going, serial, now and then, cyclic, here and there, on-again, broken, periodical, rhythmic
interrupted (part of speech: adjective)
irregular (part of speech: adjective)
- The nurse thought surely the still white face she saw in the intermittent gleams of a lamp- flame flickering out was the face of a dead man. - "Somehow Good", William de Morgan.
- She had bethought herself that this favour might, like her presence and as if depending on it, be only intermittent and for the season. - "What Maisie Knew", Henry James.
- For several minutes they plodded along the road, hidden even from the intermittent light of the moon by the trees that grew beside the road. - "Tom of the Raiders", Austin Bishop.