Skeleton bill, a bill or draft made out in blank as to the amount or payee, but signed by the acceptor. [Eng.] -- Skeleton key, a key with nearly the whole substance of the web filed away, to adapt it to avoid the wards of a lock; a master key; -- used for opening locks to which it has not been especially fitted. -- Skeleton leaf, a leaf from which the pulpy part has been removed by chemical means, the fibrous part alone remaining. -- Skeleton proof, a proof of a print or engraving, with the inscription outlined in hair strokes only, such proofs being taken before the engraving is finished. -- Skeleton regiment, a regiment which has its complement of officers, but in which there are few enlisted men. -- Skeleton shrimp (Zoöl.), a small crustacean of the genus Caprella. See Illust. under Læmodipoda.