erratic

/ɪˈræɾɪk/

/ɪˈrætɪk/

The adjective erratic describes things that are unpredictable, unusual, and that deviate from the norm. An erratic quarterback might completely confuse his receivers waiting for a pass.

Like its linguistic relative, error, the adjective erratic means "deviating from the norm," or "wrong." It also implies behavior or qualities that are unpredictable or odd. The word comes from the Latin verb errare, or "to wander" off course. In the field of geology, a rock that is erratic is unlike others in its environment because it has been transported by glacial activity. Likewise, someone driving a car that veers out of its lane is said to be driving erratically.

Definitions of erratic

1. adjective

   liable to sudden unpredictable change
   “erratic behavior”

   synonyms: fickle, mercurial, quicksilver

   changeable, changeful

   such that alteration is possible; having a marked tendency to change
2. adjective

   likely to perform unpredictably
   “erratic winds are the bane of a sailor”

   synonyms: temperamental, wayward

   undependable, unreliable

   not worthy of reliance or trust
3. adjective

   having no fixed course
   “an erratic comet”

   synonyms: planetary, wandering

   unsettled

   not settled or established