Illustrated Architecture Dictionary ........................... Illustrated FURNITURE Glossary

Pediment
PED a ment

Triangular pediment	Round/Segmental pediment
Broken pediment	Broken pediment
Swan's neck pediment	Bonnet top pediment

Pediment:  Triangular piece just under a pointed roof;  a triangular part at the top of the front of a building that supports the roof and is often decorated;  triangular gable between a horizontal entablature and a sloping roof;   a large triangular structure built over a door or window as a decoration

Pediment" is possibly a garbling of "pyramid."

Tympanum: the space inside the pediment. It is is ideal for bold sculpture, as in Greek temples.

Raking cornice: the sloping edges of a pediment

Found in Classical Greek and Roman, Neoclassical and Baroque architecture

Many classical Greek buildings have a pediment at the top, often above a row of columns. A classic pediment sits above the horizontal moulding (known as an entablature) above a window or door, which is usually supported by columns. This is true in many classical buildings, like the Greek Parthenon. You can see pediments even in relatively modern homes too, mainly in the form of a triangle or half-circle shape above a door or window. These pediments are decorative, while the originals were structural. - Vocabulary.com (online October 2020)

The pediment was the crowning feature of the Greek temple front. The Romans adapted the pediment as a purely decorative form to finish doors, windows, and especially niches. Their pediments frequently appeared in a series consisting of alternating triangular and segmentally curved shapes, a motif revived by High Renaissance Italian designers. Following a late Roman precedent, in which the line of the raking cornice is broken before it reaches the apex, the designers of the Baroque period developed many varieties of fantastic broken, scrolled, and reverse-curved pediments. -Encyclopaedia Britannica (online October 2020)