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
Antonyms: typical
Definition: exhibiting the qualities or characteristics that identify a group or kind or category
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
Antonyms: natural
Definition: in accordance with nature; relating to or concerning nature
Antonyms: normal
Definition: conforming with or constituting a norm or standard or level or type or social norm; not abnormal
Antonyms: normal
Definition: being approximately average or within certain limits in e.g. intelligence and development