"hey up" meaning in English

{
  "etymology_text": "From high up as a warning. Written heigh up by Joseph Wright in the English Dialect Dictionary. Always pronounced with the diphthong ɛɪ as was formerly used in high in these dialects. Never pronounced /e:/ as used in hay.",
  "head_templates": [
    {
      "args": {},
      "expansion": "hey up",
      "name": "en-interj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "intj",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Northern England English",
          "parents": [],
          "source": "w"
        },
        {
          "_dis": "54 46",
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        },
        {
          "_dis": "82 18",
          "kind": "other",
          "name": "English greetings",
          "parents": [],
          "source": "w+disamb"
        },
        {
          "_dis": "54 46",
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w+disamb"
        },
        {
          "_dis": "56 44",
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w+disamb"
        }
      ],
      "glosses": [
        "A greeting."
      ],
      "id": "en-hey_up-en-intj-wMikTRDM",
      "links": [
        [
          "greeting",
          "greeting"
        ]
      ],
      "raw_glosses": [
        "(Northern England, informal) A greeting."
      ],
      "tags": [
        "Northern-England",
        "informal"
      ]
    },
    {
      "categories": [
        {
          "_dis": "54 46",
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        },
        {
          "_dis": "54 46",
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w+disamb"
        }
      ],
      "glosses": [
        "Used to get attention, or as a warning."
      ],
      "id": "en-hey_up-en-intj-9sqNxEcj",
      "synonyms": [
        {
          "_dis1": "39 61",
          "word": "ey up"
        },
        {
          "_dis1": "39 61",
          "word": "'ey up"
        },
        {
          "_dis1": "39 61",
          "word": "ay oop"
        },
        {
          "_dis1": "39 61",
          "word": "ay up"
        },
        {
          "_dis1": "39 61",
          "word": "ayup"
        }
      ]
    }
  ],
  "word": "hey up"
}

{
  "categories": [
    "English entries with incorrect language header",
    "English greetings",
    "English interjections",
    "English lemmas",
    "English multiword terms",
    "Pages with 1 entry",
    "Pages with entries"
  ],
  "etymology_text": "From high up as a warning. Written heigh up by Joseph Wright in the English Dialect Dictionary. Always pronounced with the diphthong ɛɪ as was formerly used in high in these dialects. Never pronounced /e:/ as used in hay.",
  "head_templates": [
    {
      "args": {},
      "expansion": "hey up",
      "name": "en-interj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "intj",
  "senses": [
    {
      "categories": [
        "English informal terms",
        "Northern England English"
      ],
      "glosses": [
        "A greeting."
      ],
      "links": [
        [
          "greeting",
          "greeting"
        ]
      ],
      "raw_glosses": [
        "(Northern England, informal) A greeting."
      ],
      "tags": [
        "Northern-England",
        "informal"
      ]
    },
    {
      "glosses": [
        "Used to get attention, or as a warning."
      ]
    }
  ],
  "synonyms": [
    {
      "word": "ey up"
    },
    {
      "word": "'ey up"
    },
    {
      "word": "ay oop"
    },
    {
      "word": "ay up"
    },
    {
      "word": "ayup"
    }
  ],
  "word": "hey up"
}