Spasmodically (3,3,2)
I believe the answer is:
off and on
'spasmodically' is the definition.
(thesaurus)
This is all the clue.
(Other definitions for off and on that I've seen before include "Intermittently" , "the two sides at the Oval are this" , "switch positions" , "From time to time" , "Now and then, here and there (3, 3, 2)" .)