Main entry: atypical, irregular
Definition: deviating from normal expectations; somewhat odd, strange, or abnormal
Usage: these days large families are atypical; atypical clinical findings; atypical pneumonia; highly irregular behavior
Main entry: untypical, atypical
Definition: not representative of a group, class, or type
Usage: a group that is atypical of the target audience; a class of atypical mosses; atypical behavior is not the accepted type of response that we expect from children