Generally refers to the main deck where it is not protected from the weather or has no covering. Also sometimes just means outside on deck anywhere on a vessel.

Any deck is that exposed to the weather, usually either the main deck or upper deck.

Deck that is open to weather and sea.

any uncovered deck which is not protected from the weather or the sea Source: Country Life Book of Nautical Terms Under Sail

Uppermost hull deck exposed to the weather at all times.

Any deck exposed to the elements; a deck outside the skin of the ship.

Whichever deck is that exposed to the weather—usually either the main deck or, in larger vessels, the upper deck.

A term for a ship's deck having no overhead protection from the weather, it is open to the elements (weather).

A deck exposed to the wind and sea.

any deck of a ship which is exposed to the weather.

Whichever deck is that exposed to the weather – usually either the main deck or, in larger vessels, the upper deck.

The uppermost deck of a ship; any deck that does not have overhead protection from the weather.

Whichever deck is that exposed to the weather—usually either the main deck or, in larger vessels, the upper deck.

Literally, any deck of a ship which is exposed to the weather, i.e. outside the skin of the ship.

the deck that is exposed to the weather; usually either the main deck or, in larger vessels, the upper deck

A deck exposed to the wind and sea.