noun.
A narrow rectangular sail set from extensions of the yards of square-rigged ships.
The Century Dictionary and Cyclopedia
noun.
A sail set beyond the leeches of some of the principal squaresails during a fair wind, very seldom used.
Word Usage
"Chase ordered a double rum ration, hung out a larger studdingsail that the sailmaker had stitched, and watched the Revenant on the north-western horizon."