"hidro-" meaning in Spanish

{
  "etymology_templates": [
    {
      "args": {
        "1": "es",
        "2": "grc",
        "3": "ὑδρο-"
      },
      "expansion": "Borrowed from Ancient Greek ὑδρο- (hudro-)",
      "name": "bor+"
    }
  ],
  "etymology_text": "Borrowed from Ancient Greek ὑδρο- (hudro-), from ὕδωρ (húdōr, “water”).",
  "head_templates": [
    {
      "args": {
        "1": "es",
        "2": "prefix"
      },
      "expansion": "hidro-",
      "name": "head"
    }
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "prefix",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Pages with 5 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Spanish entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "hydro-"
      ],
      "id": "en-hidro--es-prefix-HOBDHqBf",
      "links": [
        [
          "hydro-",
          "hydro-"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "word": "hidro-"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "es",
        "2": "grc",
        "3": "ὑδρο-"
      },
      "expansion": "Borrowed from Ancient Greek ὑδρο- (hudro-)",
      "name": "bor+"
    }
  ],
  "etymology_text": "Borrowed from Ancient Greek ὑδρο- (hudro-), from ὕδωρ (húdōr, “water”).",
  "head_templates": [
    {
      "args": {
        "1": "es",
        "2": "prefix"
      },
      "expansion": "hidro-",
      "name": "head"
    }
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "prefix",
  "senses": [
    {
      "categories": [
        "Pages with 5 entries",
        "Pages with entries",
        "Spanish entries with incorrect language header",
        "Spanish lemmas",
        "Spanish prefixes",
        "Spanish terms borrowed from Ancient Greek",
        "Spanish terms derived from Ancient Greek"
      ],
      "glosses": [
        "hydro-"
      ],
      "links": [
        [
          "hydro-",
          "hydro-"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "word": "hidro-"
}