"mid-key" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "mid",
        "3": "key"
      },
      "expansion": "mid- + key",
      "name": "prefix"
    }
  ],
  "etymology_text": "mid- + key",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "mid-key (not comparable)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "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 terms prefixed with mid-",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Photography",
          "orig": "en:Photography",
          "parents": [
            "Art",
            "Human activity",
            "Media",
            "Culture",
            "Human behaviour",
            "Communication",
            "Society",
            "Human",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Using or relating to a level of lighting between low-key and high-key."
      ],
      "id": "en-mid-key-en-adj-Z6K-4KC8",
      "links": [
        [
          "photography",
          "photography"
        ],
        [
          "lighting",
          "lighting"
        ],
        [
          "low-key",
          "low-key"
        ],
        [
          "high-key",
          "high-key"
        ]
      ],
      "raw_glosses": [
        "(photography) Using or relating to a level of lighting between low-key and high-key."
      ],
      "tags": [
        "not-comparable"
      ],
      "topics": [
        "arts",
        "hobbies",
        "lifestyle",
        "photography"
      ]
    }
  ],
  "word": "mid-key"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "mid",
        "3": "key"
      },
      "expansion": "mid- + key",
      "name": "prefix"
    }
  ],
  "etymology_text": "mid- + key",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "mid-key (not comparable)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "English adjectives",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English terms prefixed with mid-",
        "English uncomparable adjectives",
        "en:Photography"
      ],
      "glosses": [
        "Using or relating to a level of lighting between low-key and high-key."
      ],
      "links": [
        [
          "photography",
          "photography"
        ],
        [
          "lighting",
          "lighting"
        ],
        [
          "low-key",
          "low-key"
        ],
        [
          "high-key",
          "high-key"
        ]
      ],
      "raw_glosses": [
        "(photography) Using or relating to a level of lighting between low-key and high-key."
      ],
      "tags": [
        "not-comparable"
      ],
      "topics": [
        "arts",
        "hobbies",
        "lifestyle",
        "photography"
      ]
    }
  ],
  "word": "mid-key"
}