"behind center" meaning in English

{
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "behind center (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"
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          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Football (American)",
          "orig": "en:Football (American)",
          "parents": [
            "Football",
            "Ball games",
            "Sports",
            "Human activity",
            "Human behaviour",
            "Human",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "At the quarterback position."
      ],
      "id": "en-behind_center-en-adj-neSNQEGV",
      "links": [
        [
          "American football",
          "American football"
        ],
        [
          "quarterback",
          "quarterback"
        ]
      ],
      "raw_glosses": [
        "(American football) At the quarterback position."
      ],
      "synonyms": [
        {
          "word": "under center"
        }
      ],
      "tags": [
        "not-comparable"
      ],
      "topics": [
        "American-football",
        "ball-games",
        "football",
        "games",
        "hobbies",
        "lifestyle",
        "sports"
      ]
    }
  ],
  "word": "behind center"
}

{
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "behind center (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 uncomparable adjectives",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Football (American)"
      ],
      "glosses": [
        "At the quarterback position."
      ],
      "links": [
        [
          "American football",
          "American football"
        ],
        [
          "quarterback",
          "quarterback"
        ]
      ],
      "raw_glosses": [
        "(American football) At the quarterback position."
      ],
      "tags": [
        "not-comparable"
      ],
      "topics": [
        "American-football",
        "ball-games",
        "football",
        "games",
        "hobbies",
        "lifestyle",
        "sports"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "under center"
    }
  ],
  "word": "behind center"
}