Answer: RECURS

AnswerCrossword Clue
RECURSAppears at intervals.
recursto occur again
recursto return in thought
recursRECUR, to come around at intervals
RECURSBecomes chronic
RECURSFollows a pattern
RECURSHappens more than once
RECURSRepeats itself
RECURSHappens repeatedly
RECURSComes back
RECURSComes up again.
RECURSAppears again.
RECURSHappens periodically
RECURSHappens again.
RECURSPersists
RECURSPops up again
RECURSHappens over and over
RECURSComes up again
RECURSHappens again
RECURSAppears again
RECURSHappens intermittently
RECURSHappens yet again
RECURSComes over?
RECURSKeeps happening