"acid-base indicator" meaning in English

{
  "forms": [
    {
      "form": "acid-base indicators",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "head": "acid-base indicator"
      },
      "expansion": "acid-base indicator (plural acid-base indicators)",
      "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": "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 Finnish translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Chemistry",
          "orig": "en:Chemistry",
          "parents": [
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A substance that shows the acidity or alkalinity of a solution by its colour."
      ],
      "id": "en-acid-base_indicator-en-noun-WEb6Yjpo",
      "links": [
        [
          "chemistry",
          "chemistry"
        ],
        [
          "substance",
          "substance"
        ],
        [
          "acidity",
          "acidity"
        ],
        [
          "alkalinity",
          "alkalinity"
        ],
        [
          "solution",
          "solution"
        ],
        [
          "colour",
          "colour"
        ]
      ],
      "raw_glosses": [
        "(chemistry) A substance that shows the acidity or alkalinity of a solution by its colour."
      ],
      "related": [
        {
          "word": "bromocresol purple"
        },
        {
          "word": "bromophenol blue"
        },
        {
          "word": "bromothymol blue"
        },
        {
          "word": "congo red"
        },
        {
          "word": "indigo carmine"
        },
        {
          "word": "litmus"
        },
        {
          "word": "methyl orange"
        },
        {
          "word": "methyl violet"
        },
        {
          "word": "phenolphthalein"
        },
        {
          "word": "phenol red"
        },
        {
          "word": "thymol blue"
        },
        {
          "word": "thymolphthalein"
        }
      ],
      "synonyms": [
        {
          "word": "pH indicator"
        }
      ],
      "topics": [
        "chemistry",
        "natural-sciences",
        "physical-sciences"
      ],
      "translations": [
        {
          "code": "fi",
          "lang": "Finnish",
          "sense": "substance",
          "word": "happo-emäs indikaattori"
        }
      ],
      "wikipedia": [
        "pH indicator"
      ]
    }
  ],
  "word": "acid-base indicator"
}

{
  "forms": [
    {
      "form": "acid-base indicators",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "head": "acid-base indicator"
      },
      "expansion": "acid-base indicator (plural acid-base indicators)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "bromocresol purple"
    },
    {
      "word": "bromophenol blue"
    },
    {
      "word": "bromothymol blue"
    },
    {
      "word": "congo red"
    },
    {
      "word": "indigo carmine"
    },
    {
      "word": "litmus"
    },
    {
      "word": "methyl orange"
    },
    {
      "word": "methyl violet"
    },
    {
      "word": "phenolphthalein"
    },
    {
      "word": "phenol red"
    },
    {
      "word": "thymol blue"
    },
    {
      "word": "thymolphthalein"
    }
  ],
  "senses": [
    {
      "categories": [
        "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 Finnish translations",
        "en:Chemistry"
      ],
      "glosses": [
        "A substance that shows the acidity or alkalinity of a solution by its colour."
      ],
      "links": [
        [
          "chemistry",
          "chemistry"
        ],
        [
          "substance",
          "substance"
        ],
        [
          "acidity",
          "acidity"
        ],
        [
          "alkalinity",
          "alkalinity"
        ],
        [
          "solution",
          "solution"
        ],
        [
          "colour",
          "colour"
        ]
      ],
      "raw_glosses": [
        "(chemistry) A substance that shows the acidity or alkalinity of a solution by its colour."
      ],
      "topics": [
        "chemistry",
        "natural-sciences",
        "physical-sciences"
      ],
      "wikipedia": [
        "pH indicator"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "pH indicator"
    }
  ],
  "translations": [
    {
      "code": "fi",
      "lang": "Finnish",
      "sense": "substance",
      "word": "happo-emäs indikaattori"
    }
  ],
  "word": "acid-base indicator"
}