Pronunciation: krī-tēr′ē-on, crī-tēr-ē-ă
1. A standard or rule for judging; usually plural (criteria) to denote a set of standards or rules.
2. In psychology, a standard such as school grades against which test scores on intelligence tests or other measured behaviors are validated.
3. A list of manifestations of a disease or disorder, a certain number of which must be present to warrant diagnosis in a given patient.
The definition information for criterion is provided by Stedman's. You can search our medical dictionary here.