pent(a)-

Five; having five.

Greek pente, five.

A pentagon is a plane figure with five straight sides and five angles; the athletic event called the pentathlon comprises five different events for each competitor; a pentameter is a line of verse containing five metrical feet; a pentagram is a five-pointed star, often used as a mystic and magical symbol; the Pentateuch (Greek teukhos, implement, book) is the collective name for the first five books of the Old Testament.

In chemistry, a pentavalent atom or group has a combining power of five; a pentoxide is an oxide containing five atoms of oxygen in its molecule or empirical formula; a pentose is any of the class of simple sugars whose molecules contain five carbon atoms, such as ribose and xylose.