"deep scattering layer" meaning in English

{
  "etymology_text": "From being a layer of the ocean that lies deep, and scatters sonar signals.",
  "forms": [
    {
      "form": "deep scattering layers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "deep scattering layer (plural deep scattering layers)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Oceanography",
          "orig": "en:Oceanography",
          "parents": [
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "derived": [
        {
          "word": "DSL"
        }
      ],
      "glosses": [
        "A layer of the ocean lying usually 300-500 metres deep composed of dense concentrations of pelagic animal life, that moves depending on the time of day, up at night and down during the day. It sometimes appear as if it were the seabed on sonar scopes, due to the density of life in the layer."
      ],
      "id": "en-deep_scattering_layer-en-noun-9AOjisgg",
      "links": [
        [
          "oceanography",
          "oceanography"
        ]
      ],
      "raw_glosses": [
        "(oceanography) A layer of the ocean lying usually 300-500 metres deep composed of dense concentrations of pelagic animal life, that moves depending on the time of day, up at night and down during the day. It sometimes appear as if it were the seabed on sonar scopes, due to the density of life in the layer."
      ],
      "synonyms": [
        {
          "word": "DSL"
        },
        {
          "word": "ECR layer"
        },
        {
          "word": "Eyring-Christensen-Raitt layer"
        },
        {
          "word": "false bottom"
        },
        {
          "word": "phantom bottom"
        },
        {
          "word": "sound scattering layer"
        },
        {
          "word": "SSL"
        }
      ],
      "topics": [
        "geography",
        "natural-sciences",
        "oceanography"
      ],
      "wikipedia": [
        "en:deep scattering layer"
      ]
    }
  ],
  "word": "deep scattering layer"
}

{
  "derived": [
    {
      "word": "DSL"
    }
  ],
  "etymology_text": "From being a layer of the ocean that lies deep, and scatters sonar signals.",
  "forms": [
    {
      "form": "deep scattering layers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "deep scattering layer (plural deep scattering layers)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "en:Oceanography"
      ],
      "glosses": [
        "A layer of the ocean lying usually 300-500 metres deep composed of dense concentrations of pelagic animal life, that moves depending on the time of day, up at night and down during the day. It sometimes appear as if it were the seabed on sonar scopes, due to the density of life in the layer."
      ],
      "links": [
        [
          "oceanography",
          "oceanography"
        ]
      ],
      "raw_glosses": [
        "(oceanography) A layer of the ocean lying usually 300-500 metres deep composed of dense concentrations of pelagic animal life, that moves depending on the time of day, up at night and down during the day. It sometimes appear as if it were the seabed on sonar scopes, due to the density of life in the layer."
      ],
      "topics": [
        "geography",
        "natural-sciences",
        "oceanography"
      ],
      "wikipedia": [
        "en:deep scattering layer"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "DSL"
    },
    {
      "word": "ECR layer"
    },
    {
      "word": "Eyring-Christensen-Raitt layer"
    },
    {
      "word": "false bottom"
    },
    {
      "word": "phantom bottom"
    },
    {
      "word": "sound scattering layer"
    },
    {
      "word": "SSL"
    }
  ],
  "word": "deep scattering layer"
}