A sill is an intrusive rock formation. These formations occur when magma solidifies underground and then intrudes into the overlying rock formation. They are distinct from similarly formed domes and dikes because sills are horizontal to the surface.
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). Pap smear is performed by opening the vaginal canal with a speculum, then collecting cells at the outer opening of the cervix at the transformation zone (where the outer squamous cervical cells meet the inner glandular endocervical cells).
A Pap smear is a simple, quick, and relatively painless screening test. Its specificity, which means its ability to avoid classifying a normal smear as abnormal (a false positive result), while very good, is not perfect.