"πετά-" meaning in Greek

{
  "forms": [
    {
      "form": "petá-",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "el",
        "2": "prefix",
        "head": "",
        "sort": ""
      },
      "expansion": "πετά- • (petá-)",
      "name": "head"
    },
    {
      "args": {},
      "expansion": "πετά- • (petá-)",
      "name": "el-prefix"
    }
  ],
  "lang": "Greek",
  "lang_code": "el",
  "pos": "prefix",
  "senses": [
    {
      "alt_of": [
        {
          "extra": "peta-",
          "word": "πετα-"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "Greek entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "el",
          "name": "SI units",
          "orig": "el:SI units",
          "parents": [
            "Units of measure",
            "Metrology",
            "Quantity",
            "Applied sciences",
            "Mathematics",
            "Sciences",
            "Formal sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Alternative form of πετα- (peta-)"
      ],
      "id": "en-πετά--el-prefix-Rld4uNiV",
      "links": [
        [
          "πετα-",
          "πετα-#Greek"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative",
        "morpheme"
      ]
    }
  ],
  "word": "πετά-"
}

{
  "forms": [
    {
      "form": "petá-",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "el",
        "2": "prefix",
        "head": "",
        "sort": ""
      },
      "expansion": "πετά- • (petá-)",
      "name": "head"
    },
    {
      "args": {},
      "expansion": "πετά- • (petá-)",
      "name": "el-prefix"
    }
  ],
  "lang": "Greek",
  "lang_code": "el",
  "pos": "prefix",
  "senses": [
    {
      "alt_of": [
        {
          "extra": "peta-",
          "word": "πετα-"
        }
      ],
      "categories": [
        "Greek entries with incorrect language header",
        "Greek lemmas",
        "Greek prefixes",
        "Pages with 1 entry",
        "Pages with entries",
        "el:SI units"
      ],
      "glosses": [
        "Alternative form of πετα- (peta-)"
      ],
      "links": [
        [
          "πετα-",
          "πετα-#Greek"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative",
        "morpheme"
      ]
    }
  ],
  "word": "πετά-"
}