Bressummer

A bressummer, breastsummer, summer beam (somier, sommier, sommer, somer, cross-somer, summer, summier,[1] summer-tree,[2] or dorman, dormant tree) is a load-bearing beam in a timber-framed building.

The word summer derived from sumpter or French sommier, "a pack horse", meaning "bearing great burden or weight".

"To support a superincumbent wall", "any beast of burden", and in this way is similar to a wall plate.

The use and definition of these terms vary but generally a bressummer is a jetty sill and a summer is an interior beam supporting ceiling joists, see below:

A typical summer beam with slender joists in the ceiling of a cafe in the Netherlands. Image: Cultural Heritage Agency of the Netherlands.