"Tbn." meaning in French

{
  "etymology_templates": [
    {
      "args": {
        "1": "fr",
        "2": "trombone",
        "3": ""
      },
      "expansion": "Abbreviation of trombone",
      "name": "abbrev"
    }
  ],
  "etymology_text": "Abbreviation of trombone.",
  "forms": [
    {
      "form": "Tbn.",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "m",
        "2": "#"
      },
      "expansion": "Tbn. m (plural Tbn.)",
      "name": "fr-noun"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "French entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "fr",
          "name": "Music",
          "orig": "fr:Music",
          "parents": [
            "Art",
            "Sound",
            "Culture",
            "Energy",
            "Society",
            "Nature",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Tbn."
      ],
      "id": "en-Tbn.-fr-noun-~0nTSRbj",
      "links": [
        [
          "music",
          "music"
        ],
        [
          "Tbn.",
          "Tbn.#English"
        ]
      ],
      "raw_glosses": [
        "(music) Tbn."
      ],
      "tags": [
        "masculine"
      ],
      "topics": [
        "entertainment",
        "lifestyle",
        "music"
      ]
    }
  ],
  "word": "Tbn."
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "fr",
        "2": "trombone",
        "3": ""
      },
      "expansion": "Abbreviation of trombone",
      "name": "abbrev"
    }
  ],
  "etymology_text": "Abbreviation of trombone.",
  "forms": [
    {
      "form": "Tbn.",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "m",
        "2": "#"
      },
      "expansion": "Tbn. m (plural Tbn.)",
      "name": "fr-noun"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "French abbreviations",
        "French countable nouns",
        "French entries with incorrect language header",
        "French lemmas",
        "French masculine nouns",
        "French nouns",
        "French terms spelled with .",
        "fr:Music"
      ],
      "glosses": [
        "Tbn."
      ],
      "links": [
        [
          "music",
          "music"
        ],
        [
          "Tbn.",
          "Tbn.#English"
        ]
      ],
      "raw_glosses": [
        "(music) Tbn."
      ],
      "tags": [
        "masculine"
      ],
      "topics": [
        "entertainment",
        "lifestyle",
        "music"
      ]
    }
  ],
  "word": "Tbn."
}