noun. a long steep-sided depression in the ocean floor.
adjective. ['ˌoʊʃiːˈænɪk'] resembling the ocean in apparent limitlessness in extent or degree.
adjective. ['ˌoʊʃiːˈænɪk'] constituting or living in the open sea.
adjective. ['ˌoʊʃiːˈænɪk'] relating to or occurring or living in or frequenting the open ocean.