United States Navy (usually, but can be any nation's fleet). The Navy is the sea-based branch of the military, but through the use of aircraft carriers they have taken over much of what the Air Force used to do. Because of this they are possibly the most prominent and widely-used of all the branches of the U.S. military (same goes for most other nations too). Tactically, their primary focus is blue-water operations such as fleet and subarmine warfare, but since the Cold War this role has been de-emphasized as most countries with any respectable naval forces arent dumb enough to piss off the USA.
Their role in combat operations will likely only continue to increase as everyone loves a "clean" airwar. However, because they do not have a true ground force anymore they are not self-sufficient and must work very closely with the Army/Marines during combat operations.
The Army and Marines move in to take over territory after the Navy and Air Force have turned it into a big smoking crater.
An acronym which stands for Never Again Volunteer Yourself. Popular among junior enlisted sailors when they are feeling especially bitter about the fact that they always have to strip and wax the 'deck' and clean the 'head'. Officers and senior enlisted (lifers) do not approve of this acronym or its usage.
The term is beginning to find some usage amongst the civilian population as well, usually after someone has volunteered him or herself to do something, only to have it turn into a giant pain in the ass that you can't get out of.
Regardless of the particular context, the term is always used while bitching about something.
Johnny: This sucks!!
Steven: Navy, dude. Navy.
Johnny: Yup. Navy.
You also sometimes hear it as a direct substitute for words like shitty, sucks, bullshit, etc.
Example: Johnny: This is so fucking Navy!!
Branch of the US military that primarily handles sea operations. The Navy also has air forces (naval aviators), ground forces (USMC is under the Department of the Navy), and special forces (SEALS, DEVGRU). The USN transports and provides support to Marines, along with anti-piracy operations and other duties. During the Cold War the Navy ran a huge intelligence program against the Soviet Union using submarines.
The finest branch of the United States Military. Even though people question the need for a Navy in modern era, but the fail to recognize its abilities.
Provides long-range, heavy artilery fire for land and amphibious units
Provides forward operations and launch point for aircraft
Transports those damned Marines
And need I mention the SEALs and SWCCs?
I joined the navy so I could become a SEAL. After all, they are the best in the world.