ocean
noun
ˈəʊʃn 
ˈoʊʃn 
1 (usually the ocean) [singular] (especially North American English) the mass of salt water that covers most of the earth's surfacethe depths of the oceanPeople were swimming in the ocean despite the hurricane warning.The plane hit the ocean several miles offshore.Our beach house is just a couple of miles from the ocean.an ocean linerOcean levels are rising.2 (usually Ocean) [countable] one of the five large areas that the ocean is divided intothe Antarctic/Arctic/Atlantic/Indian/Pacific Ocean Idioms
an ocean of something
(British English also oceans of something) (informal) a large amount of something
Usage note: sea / oceanIn British English, the usual word for the mass of salt water that covers most of the earth’s surface is the sea. In North American English, the usual word is the ocean: A swimmer drowned in the sea/ocean this morning.The names of particular areas of seas, however, are fixed: the Mediterranean Sea ◇ the Atlantic Ocean.Sea/ocean are also used if you go to the coast on holiday/vacation: We’re spending a week by the sea/at the ocean in June. In North American English it is also common to say: We’re going to the beach for vacation. note at coast