The Papanicolaou test (abbreviated as Pap test, known earlier as Pap smear, cervical smear, or smear test) is a method of cervical screening used to detect potentially pre-cancerous and cancerous processes in the cervix (opening of the uterus or womb).hile the test may also detect infections and abnormalities in the endocervix and endometrium, it is not designed to do so. In the United States, Pap smear screening is recommended starting around 21 years of age until the age of 65. Guidelines on frequency vary from every three to five years.