"test pattern" meaning in English

{
  "forms": [
    {
      "form": "test patterns",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "test pattern (plural test patterns)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "American English",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Entries with translation boxes",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Japanese translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Korean translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Television",
          "orig": "en:Television",
          "parents": [
            "Broadcasting",
            "Mass media",
            "Media",
            "Telecommunications",
            "Culture",
            "Communication",
            "Technology",
            "Society",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A test signal, typically broadcast at times when the transmitter is active but no program is being broadcast."
      ],
      "id": "en-test_pattern-en-noun-N1fNYoLB",
      "links": [
        [
          "television",
          "television"
        ],
        [
          "signal",
          "signal"
        ],
        [
          "program",
          "program"
        ]
      ],
      "raw_glosses": [
        "(US, television) A test signal, typically broadcast at times when the transmitter is active but no program is being broadcast."
      ],
      "synonyms": [
        {
          "word": "test card"
        }
      ],
      "tags": [
        "US"
      ],
      "topics": [
        "broadcasting",
        "media",
        "television"
      ],
      "translations": [
        {
          "code": "ja",
          "lang": "Japanese",
          "roman": "tesuto patān",
          "sense": "Translations",
          "word": "テストパターン"
        },
        {
          "code": "ko",
          "lang": "Korean",
          "roman": "teseuteu paeteon",
          "sense": "Translations",
          "word": "테스트 패턴"
        }
      ],
      "wikipedia": [
        "test pattern"
      ]
    }
  ],
  "word": "test pattern"
}

{
  "forms": [
    {
      "form": "test patterns",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "test pattern (plural test patterns)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "American English",
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Entries with translation boxes",
        "Pages with 1 entry",
        "Pages with entries",
        "Terms with Japanese translations",
        "Terms with Korean translations",
        "Translation table header lacks gloss",
        "en:Television"
      ],
      "glosses": [
        "A test signal, typically broadcast at times when the transmitter is active but no program is being broadcast."
      ],
      "links": [
        [
          "television",
          "television"
        ],
        [
          "signal",
          "signal"
        ],
        [
          "program",
          "program"
        ]
      ],
      "raw_glosses": [
        "(US, television) A test signal, typically broadcast at times when the transmitter is active but no program is being broadcast."
      ],
      "tags": [
        "US"
      ],
      "topics": [
        "broadcasting",
        "media",
        "television"
      ],
      "wikipedia": [
        "test pattern"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "test card"
    }
  ],
  "translations": [
    {
      "code": "ja",
      "lang": "Japanese",
      "roman": "tesuto patān",
      "sense": "Translations",
      "word": "テストパターン"
    },
    {
      "code": "ko",
      "lang": "Korean",
      "roman": "teseuteu paeteon",
      "sense": "Translations",
      "word": "테스트 패턴"
    }
  ],
  "word": "test pattern"
}