The internal side walls of the door and window openings that support a lintel or an arch are usually called jambs. A jamb is also a stone or brick pillar, located in the thickness of a wall, whose purpose is to consolidate and lock the pieces of the set. The jambs are usually made of masonry, brick or wood.

The word jamb comes from the French language: jambe,[1]​ which means leg, a term used due to the similarity of its supporting function.

Vitruvius Pollio, in the Compendium of Vitruvius' ten books of Architecture, written in 1761, states:

However, this definition is more in line with the current term jambaje.

Diego Antonio Rejón de Silva, in the Dictionary of the Noble Arts, of 1788, states:

Benito Bails in his Dictionary of Civil Architecture, from 1802, defines jamb as:.

Jambaje is the set of the two jambs and the lintel that make up the frame of a door or window. Everything pertaining to the decoration of the jambs and the lintel.[5]​.