"usefuller" meaning in English

{
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "comparative adjective"
      },
      "expansion": "usefuller",
      "name": "head"
    }
  ],
  "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"
          ],
          "source": "w"
        }
      ],
      "form_of": [
        {
          "extra": "more useful",
          "word": "useful"
        }
      ],
      "glosses": [
        "comparative form of useful: more useful"
      ],
      "id": "en-usefuller-en-adj-JOMG8Nyl",
      "links": [
        [
          "useful",
          "useful#English"
        ]
      ],
      "raw_glosses": [
        "(rare) comparative form of useful: more useful"
      ],
      "tags": [
        "comparative",
        "form-of",
        "rare"
      ]
    }
  ],
  "word": "usefuller"
}

{
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "comparative adjective"
      },
      "expansion": "usefuller",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "English comparative adjectives",
        "English entries with incorrect language header",
        "English non-lemma forms",
        "English terms with rare senses"
      ],
      "form_of": [
        {
          "extra": "more useful",
          "word": "useful"
        }
      ],
      "glosses": [
        "comparative form of useful: more useful"
      ],
      "links": [
        [
          "useful",
          "useful#English"
        ]
      ],
      "raw_glosses": [
        "(rare) comparative form of useful: more useful"
      ],
      "tags": [
        "comparative",
        "form-of",
        "rare"
      ]
    }
  ],
  "word": "usefuller"
}