6 letters · 12 points in Scrabble
adjective occurring in spells and often abruptly
adjective intermittently stopping and starting
originFrom fit (“convulsion, seizure; sudden burst of activity”) + -ful (suffix forming adjectives from nouns, with the sense of being full of, tending to, or thoroughly possessing the quality expressed by the noun).
Etymology from Wiktionary, CC BY-SA 3.0