Ébauche is a French term meaning "outline". In horology the term refers to an incomplete watch movement.
Until about 1850, the "ébauche" consisted only of the bottom plate, bars, fusee , and barrel.
In the early 19th Century, the "ébauche", was made up of two plates with pillars and bars, the barrel, fusee, index , click and ratchet-wheel, and a few assembling screws. These parts were all roughly filed and milled. The steel and brass were manufactured in special workshop. The "ébauche" was finished by watchmakers in the finishing-shops . Then came the application of the industrial revolution at the Waltham Watch Company, founded by Aaron Lufkin Dennison, and the developement of the American System of Watch Manufacturing, establishing the base of modern watch manufacture.
The modern "ébauche" is a jeweled watch movement, without its regulating organs, mainspring, dial, or hands.