As adjectives the difference between atypical and nontypical
is that atypical is not conforming to the normal type while nontypical is not typical.
As a noun atypical
is (pharmacy) an atypical antipsychotic.
atypical
English
Adjective
(
en adjective)
Not conforming to the normal type.
Unusual or irregular.
Noun
(
en noun)
(pharmacy) An atypical antipsychotic.