The minimum number of employees needed to operate a business during a vacation, weekend, or other period when people do not normally work, or full staffing is not necessary.

plural of skeleton staff

(idiomatic) The minimum number of personnel needed to operate and maintain an item at its most simple operating requirements, such as a ship or business, during an emergency or shutdown, and at the same time, to keep vital functions operating.

(biology) a fluid-filled cavity that surrounds the soft bodies of certain invertebrates such as jellyfish

plural of skeleton in the cupboard

A very simple design of key that usually has a cylindrical shaft (sometimes called a "shank") and a single, minimal flat, rectangular tooth or "bit".

(US, idiomatic) A shameful secret.

plural of skeleton in the closet

(UK, idiomatic) A shameful secret.

(paleontology) A fossil skeleton found all in one piece with the bones still arranged in the proper order.