adjective.
Occurring in or characterized by intermittent bursts, as of activity; irregular.
The Century Dictionary and Cyclopedia
Varied by irregular fits of action and repose; occurring or marked by fits and starts; spasmodic; capricious; changeable; checkered: as, a fitful disease or mood; a fitful life or career.
Synonyms Irregular, variable, unstable.
the GNU version of the Collaborative International Dictionary of English
adjective.
Full of fits; irregularly variable; impulsive and unstable.
adjective.Irregular; unsteady; characterized by fits.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adjective.
intermittently stopping and starting
adjective.
occurring in spells and often abruptly
Word Usage
"You could see the eroded gaps when someone underbought a book and it sold out, selling in fitful gaps whenever a stock-starved store managed to get their hands on a few copies."