"drift space" meaning in English

{
  "forms": [
    {
      "form": "drift spaces",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "drift space (plural drift spaces)",
      "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": "topical",
          "langcode": "en",
          "name": "Electricity",
          "orig": "en:Electricity",
          "parents": [
            "Electromagnetism",
            "Physics",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "The space in an electron tube in which there is no modulated field"
      ],
      "id": "en-drift_space-en-noun-NvW3XvWq",
      "links": [
        [
          "electron tube",
          "electron tube"
        ],
        [
          "modulated",
          "modulated"
        ],
        [
          "field",
          "field"
        ]
      ]
    }
  ],
  "word": "drift space"
}

{
  "forms": [
    {
      "form": "drift spaces",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "drift space (plural drift spaces)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "en:Electricity"
      ],
      "glosses": [
        "The space in an electron tube in which there is no modulated field"
      ],
      "links": [
        [
          "electron tube",
          "electron tube"
        ],
        [
          "modulated",
          "modulated"
        ],
        [
          "field",
          "field"
        ]
      ]
    }
  ],
  "word": "drift space"
}