Apron

A structural support placed at right angles to the underside of a shelf, chair seat, or table top to provide additional weight bearing strength and often decorative flourishes.

Filigree

Primarily refers to fine, ornate metalwork (mainly in gold, silver, or copper), that is intricately patterned and used as ornamentation or embellishment, particularly in fine jewelry making. More broadly, the term can refer to any ornamental openwork that is delicate or fine that resembles a metal filigree in its pattern, but in other mediums.

Finial

An ornamental, terminating piece that extends vertically from the apex of a design. In architecture, they are found at the tips of gables or spires, and in furniture, as top ornaments on cabinet corners, posts, or supports. Finial also refers to the decorative metal piece used to affix lampshades to table and floor lamps. They often take the shape of a ball, flame, flower, acorn, pineapple, or vase.

Stretcher

A stretchers is a stabilizing support rail which runs horizontally between furniture legs. These often form X, H, or Y shapes in conjunction with the outside rails.