An informal (and often unacknowledged) barrier to promotion or advancement for younger people, as a result of older people continuing to work instead of retiring.

(pathology) A myoblastoma composed of granule cells

(immunology) A subtype of T cell that helps the activity of other immune cells by releasing cytokines, playing an important role in the adaptive immune system.

(immunology) A helper T cell.

ceaselessly; continually

(cytology) Any cell that has radiating dendritic processes

plural of Celtic field

A small field showing evidence of prehistoric agriculture, found in northwest Europe.

hydraulic cement

plural of celestial sphere