armada
A large group of warships sailing together for battle.
An armada is a large fleet of warships. The word originally referred to the Spanish Armada of 1588, when Spain sent 130 enormous sailing ships to invade England. That famous armada failed spectacularly: storms and English naval tactics destroyed or scattered most of the Spanish fleet before it could land troops.
Today, armada can describe any impressive collection of naval vessels, especially when they're sailing together for a military purpose. A nation might send an armada to protect its coastline or project power across an ocean. During World War II, both sides assembled armadas for major naval battles.
The word has expanded beyond strictly military uses. People sometimes call any large group of vehicles or vessels an armada: a news report might describe an armada of fishing boats heading out to sea, or an armada of trucks delivering supplies after a natural disaster. The word always suggests both large numbers and organized purpose, like when someone jokes about an armada of school buses arriving for a field trip.