What is "storm sail"

Storm \Storm\, n. [AS. storm; akin to D. storm, G. sturm, Icel. stormr; and perhaps to Gr. ? assault, onset, Skr. s? to flow, to hasten, or perhaps to L. sternere to strew, prostrate (cf. Stratum). [root]166.]

1. A violent disturbance of the atmosphere, attended by wind, rain, snow, hail, or thunder and lightning; hence, often, a heavy fall of rain, snow, or hail, whether accompanied with wind or not.

   We hear this fearful tempest sing, Yet seek no shelter to avoid the storm.
   --Shak.

2. A violent agitation of human society; a civil, political, or domestic commotion; sedition, insurrection, or war; violent outbreak; clamor; tumult.

   I will stir up in England some black storm.
   --Shak.

   Her sister Began to scold and raise up such a storm.
   --Shak.

3. A heavy shower or fall, any adverse outburst of tumultuous force; violence.

   A brave man struggling in the storms of fate.
   --Pope.

4. (Mil.) A violent assault on a fortified place; a furious attempt of troops to enter and take a fortified place by scaling the walls, forcing the gates, or the like.

   Note: Storm is often used in the formation of self-explained compounds; as, storm-presaging, stormproof, storm-tossed, and the like.

   Anticyclonic storm (Meteor.), a storm characterized by a central area of high atmospheric pressure, and having a system of winds blowing spirally outward in a direction contrary to that cyclonic storms. It is attended by low temperature, dry air, infrequent precipitation, and often by clear sky. Called also high-area storm, anticyclone. When attended by high winds, snow, and freezing temperatures such storms have various local names, as blizzard, wet norther, purga, buran, etc.

   Cyclonic storm. (Meteor.) A cyclone, or low-area storm. See Cyclone, above.

   Magnetic storm. See under Magnetic.

   Storm-and-stress period [a translation of G. sturm und drang periode], a designation given to the literary agitation and revolutionary development in Germany under the lead of Goethe and Schiller in the latter part of the 18th century.

   Storm center (Meteorol.), the center of the area covered by a storm, especially by a storm of large extent.

   Storm door (Arch.), an extra outside door to prevent the entrance of wind, cold, rain, etc.; -- usually removed in summer.

   Storm path (Meteorol.), the course over which a storm, or storm center, travels.

   Storm petrel. (Zo["o]l.) See Stormy petrel, under Petrel.

   Storm sail (Naut.), any one of a number of strong, heavy sails that are bent and set in stormy weather.

   Storm scud. See the Note under Cloud.

   Syn: Tempest; violence; agitation; calamity.

   Usage: Storm, Tempest. Storm is violent agitation, a commotion of the elements by wind, etc., but not necessarily implying the fall of anything from the clouds. Hence, to call a mere fall or rain without wind a storm is a departure from the true sense of the word. A tempest is a sudden and violent storm, such as those common on the coast of Italy, where the term originated, and is usually attended by a heavy rain, with lightning and thunder.

   Storms beat, and rolls the main; O! beat those storms, and roll the seas, in vain.
   --Pope.

   What at first was called a gust, the same Hath now a storm's, anon a tempest's name.
   --Donne.