an organization of military vessels belonging to a country and available for sea warfare
"The navy intercepted the smuggler's ship before it could reach international waters."
the navy of the United States of America; the agency that maintains and trains and equips combat-ready naval forces
"The entire fleet mobilized when the Navy received orders to deploy ships for the humanitarian mission."
A country's entire sea force, including ships and personnel.
"The new aircraft carrier will significantly boost our navy's ability to protect trade routes in the Pacific."
In plain English: A navy is a large group of warships that belong to a country's military and protect it at sea.
"The navy is responsible for protecting the country's coastlines and waters from threats."
Usage: Use navy to refer specifically to a nation's organized military forces responsible for naval warfare, such as "the United States Navy." Do not use it to describe a dark blue color or clothing, which are distinct meanings of the same word.
Having the dark blue colour of navy blue.
"She decided to paint her front door a crisp navy color to match the trim perfectly."
In plain English: Navy describes something that is very dark blue, like the color worn by sailors.
"She wore a navy blue dress to the wedding."
Usage: Use "navy" as an adjective to describe anything colored like the deep blue worn by sailors, such as a navy suit or navy pants. Do not use it when referring to the military branch itself, which requires the phrase "U.S. Navy" or similar specific designations.
The word navy comes from the Latin navis, meaning "boat," and entered Middle English via Anglo-Norman and Old French. It was borrowed to describe a fleet of ships, eventually replacing the native Old English term sċiphere, which literally meant "ship army."