Unusual, or not fitting a single diagnostic

Deviating from the normal; not typical.

unusual, not characteristic.

1847, from a- (2) "not" + typical. Related: Atypically.

differing from the norm in some manner - being unusual, unrepresentative, or uncharacteristic in some way.

in DSM-IV-TR, a category of personality disorders for which there is insufficient evidence for a more specific designation - that is, the person does not meet criteria for one particular personality d [..]

unusual (pop)

In a psychological diagnosis "atypical" refers to symptoms that are recognized as part of mental illnesses yet do not rise to the level needed for diagnosis as part of recognized syndromes o [..]

(adj) not representative of a group, class, or type(adj) deviating from normal expectations; somewhat odd, strange, or abnormal

Literally, "not typical." Exhibits unusual characteristics. For example, atypical hyperplasia is a dangerous increase in the number of breast cells; a sign that breast cancer may dev [..]

Definition: (ay-TIP-ee-kull) Not like any type or kind; irregular or unusual.

unusual, not normal, or irregular

something that is irregular; an unusual type atypical Hemolytic Uremic Syndrome (aHUS): a disease of the blood that causes low red blood cell and platelet counts, kidney failure, and damage to other vital organs, such as the heart and brain