The nature of possible underlying disease states including cancer or infections can often be detected by microscopically visualizing cytological changes in cells which are exfoliated and captured by fluid extraction from body cavity, brushings, washings, or fine needle aspirations.
Cloister definition, a covered walk, especially in a religious institution, having an open arcade or colonnade usually opening onto a courtyard. See more.
Princeton's WordNet(0.00 / 0 votes)Rate this definition: aster(noun) any of various chiefly fall-blooming herbs of the genus Aster with showy daisylike flowers. aster(noun) star-shaped structure formed in the cytoplasm of a cell having fibers like rays that surround the centrosome during mitosis.