"Tester" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "fro",
        "3": "testard",
        "4": "",
        "5": "someone with a big head"
      },
      "expansion": "Old French testard (“someone with a big head”)",
      "name": "der"
    }
  ],
  "etymology_text": "From Old French testard (“someone with a big head”), a pejorative from teste (“head”).",
  "forms": [
    {
      "form": "Testers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "Testers"
      },
      "expansion": "Tester (plural Testers)",
      "name": "en-proper noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "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 surnames",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "A surname from Old French."
      ],
      "id": "en-Tester-en-name-0tkWYPLU",
      "links": [
        [
          "surname",
          "surname"
        ]
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ˈtɛstə(ɹ)/"
    }
  ],
  "word": "Tester"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "fro",
        "3": "testard",
        "4": "",
        "5": "someone with a big head"
      },
      "expansion": "Old French testard (“someone with a big head”)",
      "name": "der"
    }
  ],
  "etymology_text": "From Old French testard (“someone with a big head”), a pejorative from teste (“head”).",
  "forms": [
    {
      "form": "Testers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "Testers"
      },
      "expansion": "Tester (plural Testers)",
      "name": "en-proper noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English lemmas",
        "English proper nouns",
        "English surnames",
        "English surnames from Old French",
        "English terms derived from Old French",
        "English uncountable nouns",
        "Pages with 1 entry"
      ],
      "glosses": [
        "A surname from Old French."
      ],
      "links": [
        [
          "surname",
          "surname"
        ]
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ˈtɛstə(ɹ)/"
    }
  ],
  "word": "Tester"
}