"flat spot" meaning in English

{
  "forms": [
    {
      "form": "flat spots",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "flat spot (plural flat spots)",
      "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"
        }
      ],
      "glosses": [
        "A small patch of a vehicle tyre that has been flattened by abrasion with the road surface, so that the tyre is no longer smoothly circular at that point; usually caused by the wheel locking under heavy braking."
      ],
      "id": "en-flat_spot-en-noun-pqSrdK4b",
      "related": [
        {
          "word": "flat-spot"
        }
      ]
    }
  ],
  "word": "flat spot"
}

{
  "forms": [
    {
      "form": "flat spots",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "flat spot (plural flat spots)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "flat-spot"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns"
      ],
      "glosses": [
        "A small patch of a vehicle tyre that has been flattened by abrasion with the road surface, so that the tyre is no longer smoothly circular at that point; usually caused by the wheel locking under heavy braking."
      ]
    }
  ],
  "word": "flat spot"
}