Erratic
Part of speech: adjective
Definition: unsteady, random; prone to unexpected changes; not consistent
Part of speech: noun
Definition: a rock moved by geologic forces from one location to another, usually by a glacier Anything that has erratic characteristics
Example sentence: I was a foggy, erratic teenager: a fifth child, the last in the queue for conversation or attention.
Undependable
Part of speech: adjective
Definition: The opposite of dependable