by
irregular or intermittent periods of
action; at varying intervals; impulsively and irregularly. A
fit is a sudden, shortlived
state of activity or inactivity, or of any specified
type of activity, feeling, etc. A start is a
brief, sudden
movement or
action from being still. To do something by fits and starts means to do it for a
period and then
stop, and then later do it again and then
stop, etc.