Tas-de-charge is a French language

French language

French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...

 term in architecture

Architecture

Architecture is both the process and product of planning, designing and construction. Architectural works, in the material form of buildings, are often perceived as cultural and political symbols and as works of art...

, for which there is no equivalent in English, given to the lower courses of ribs of a Gothic vault

Vault (architecture)

A Vault is an architectural term for an arched form used to provide a space with a ceiling or roof. The parts of a vault exert lateral thrust that require a counter resistance. When vaults are built underground, the ground gives all the resistance required...

, which are laid in horizontal courses and bonded into the wall, forming a solid mass; this helps bond the ribs, vault and walls together. They generally rise about one-third of the height of the vault, and as they project forwards they lessen the span to be vaulted over.