Merriam-Webster Collegiate Dictionary - fitful

 adjective  Date: 1592  1. obsolete characterized by fits or paroxysms  2. having an erratic or intermittent character ; irregular  • ~ly adverb  • ~ness noun Synonyms:  ~, spasmodic, convulsive mean lacking steadiness or regularity in movement. ~ implies intermittence, a succession of starts and stops or risings and fallings ~ sleep. spasmodic adds to ~ the implication of rapid or violent activity alternating with inactivity spasmodic growth. convulsive suggests the breaking of regularity or quiet by uncontrolled movement convulsive shocks.