Cytologic smear is a diagnostic test that is used to examine cells for abnormal growth or cancer. Synonyms for cytologic smear include Pap test, Papanicolaou test, cervical smear, cervical screening, and liquid-based cytology. These terms are often interchangeable, though some may be more specific to certain body parts or types of samples. In addition to diagnosing cancer, cytologic smear tests can also be used to detect infections or other abnormalities in cells. It is an important screening tool for preventing and treating cervical cancer, and is recommended for women over the age of 21 who are sexually active or have a family history of cervical cancer.