erratic
/ɪˈɹætɪk/
noun
Meaning
A rock moved from one location to another, usually by a glacier.
Anything that has erratic characteristics.
Synonyms
adjective
Meaning
Unsteady, random; prone to unexpected changes; not consistent
"Henry has been getting erratic scores on his tests: 40% last week, but 98% this week."
Deviating from normal opinions or actions; eccentric; odd.
"erratic conduct"