"I've never heard it called that before" meaning in English

{
  "etymology_text": "The word \"it\" refers to a sex act, bodily organ, etc. for which the speaker's phrase might be construed as a euphemism.",
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "phrase",
        "head": "I've never heard it called that before"
      },
      "expansion": "I've never heard it called that before",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "phrase",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with language name categories using raw markup",
          "parents": [
            "Entries with language name categories using raw markup",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English sentences",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms with non-redundant non-automated sortkeys",
          "parents": [
            "Terms with non-redundant non-automated sortkeys",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Used to draw attention to a possible double entendre in the immediately preceding utterance of another speaker."
      ],
      "id": "en-I've_never_heard_it_called_that_before-en-phrase-jvw~b62d",
      "links": [
        [
          "double entendre",
          "double entendre#English"
        ]
      ],
      "raw_glosses": [
        "(informal) Used to draw attention to a possible double entendre in the immediately preceding utterance of another speaker."
      ],
      "related": [
        {
          "word": "that's what she said"
        }
      ],
      "tags": [
        "informal"
      ]
    }
  ],
  "word": "I've never heard it called that before"
}

{
  "etymology_text": "The word \"it\" refers to a sex act, bodily organ, etc. for which the speaker's phrase might be construed as a euphemism.",
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "phrase",
        "head": "I've never heard it called that before"
      },
      "expansion": "I've never heard it called that before",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "phrase",
  "related": [
    {
      "word": "that's what she said"
    }
  ],
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English entries with language name categories using raw markup",
        "English informal terms",
        "English lemmas",
        "English multiword terms",
        "English phrases",
        "English sentences",
        "English terms with non-redundant non-automated sortkeys"
      ],
      "glosses": [
        "Used to draw attention to a possible double entendre in the immediately preceding utterance of another speaker."
      ],
      "links": [
        [
          "double entendre",
          "double entendre#English"
        ]
      ],
      "raw_glosses": [
        "(informal) Used to draw attention to a possible double entendre in the immediately preceding utterance of another speaker."
      ],
      "tags": [
        "informal"
      ]
    }
  ],
  "word": "I've never heard it called that before"
}