'Studding sail' definitions:

Definition of 'Studding sail'

From: GCIDE

Studding sail \Stud"ding sail`\ (Naut.) A light sail set at the side of a principal or square sail of a vessel in free winds, to increase her speed. Its head is bent to a small spar which is called the studding-sail boom. See Illust. of Sail. --Toten. [1913 Webster]