/ˈəʊʃ(ə)n/

noun

1.  A very large expanse of sea, in particular each of the main areas into which the sea is divided geographically.  
synonyms: the deep, the waves, the main, the foam, the profound

 

2.1 the ocean (North American) The sea. ‘they scramble across the beach to the ocean and plunge into the surf’

            2.2  (an ocean of/oceans of) informal A very large expanse or quantity. ‘she had oceans of energy’

  origin

                  Middle English from Old French ocean, via Latin from Greek ōkeanos ‘great   stream encircling the earth's disc’.

‘The ocean’ originally denoted the whole body of water regarded as encompassing the earth's single land mass.