The term “lampe gras” is French for “pig fat.” It is a type of lamp that was used in the 17th century and was made from a pig’s bladder filled with oil, which gave off a light similar to that of a candle.

The term "lampe gras" comes from the French phrase "lampes grasse," or "fat lamps." This refers to the shape of these lamps, which were originally made from pigs' bladders filled with oil and shaped into an inverted cone.

A typical lamp gras (or lampion) consists of an oil-filled bladder attached to a wick by means of a metal tube. The bladder is attached to the wick by means of some kind of clamping device.