Meanwhile still more projectiles, now with the swift sinister whistle of a cannon ball, now with the agreeable intermittent whistle of a shell, flew over people’s heads incessantly, but not one fell close by, they all flew over.
To that end Kutuzov’s activity was directed during the whole campaign from Moscow to Vilna—not casually or intermittently but so consistently that he never once deviated from it.
There are no more uses of "intermittent" in the book.
Show samples from other sources
During the day it was never far from her immediate consciousness, intermittently returning at unsuspected moments, whispering and taunting her.
Harper Lee -- Go Set a Watchman
They sat on a low hill, two salads between them, the sun making intermittent, appearances behind slow-moving clouds.