"undersock" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "under",
        "3": "sock"
      },
      "expansion": "under- + sock",
      "name": "prefix"
    }
  ],
  "etymology_text": "under- + sock",
  "forms": [
    {
      "form": "undersocks",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "undersock (plural undersocks)",
      "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": "English entries with topic categories using raw markup",
          "parents": [
            "Entries with topic categories using raw markup",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms prefixed with under-",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Footwear",
          "orig": "en:Footwear",
          "parents": [
            "Clothing",
            "Human",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A thermal sock worn under a normal sock for extra warmth."
      ],
      "id": "en-undersock-en-noun-9pKLuNa1",
      "links": [
        [
          "thermal",
          "thermal"
        ],
        [
          "sock",
          "sock"
        ],
        [
          "warmth",
          "warmth"
        ]
      ]
    }
  ],
  "word": "undersock"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "under",
        "3": "sock"
      },
      "expansion": "under- + sock",
      "name": "prefix"
    }
  ],
  "etymology_text": "under- + sock",
  "forms": [
    {
      "form": "undersocks",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "undersock (plural undersocks)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English entries with topic categories using raw markup",
        "English lemmas",
        "English nouns",
        "English terms prefixed with under-",
        "en:Footwear"
      ],
      "glosses": [
        "A thermal sock worn under a normal sock for extra warmth."
      ],
      "links": [
        [
          "thermal",
          "thermal"
        ],
        [
          "sock",
          "sock"
        ],
        [
          "warmth",
          "warmth"
        ]
      ]
    }
  ],
  "word": "undersock"
}