1. (

• atypical ,
• untypical ,
• atypic

) not representative of a group, class, or type; "a class of atypical mosses"; "atypical behavior is not the accepted type of response that we expect from children" ;

2. (

• atypical ,
• irregular

) deviating from normal expectations; somewhat odd, strange, or abnormal; "these days large families are atypical"; "atypical clinical findings"; "atypical pneumonia"; "highly irregular behavior" ;