"on call" meaning in English

{
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "prepositional phrase",
        "head": ""
      },
      "expansion": "on call",
      "name": "head"
    },
    {
      "args": {},
      "expansion": "on call",
      "name": "en-PP"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "prep_phrase",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "derived": [
        {
          "word": "on firecall"
        }
      ],
      "examples": [
        {
          "text": "1984-1986, Lou Sullivan, personal diary, quoted in 2019, Ellis Martin, Zach Ozma (editors), We Both Laughed In Pleasure\nKnow I cannot rely on him to do anything for me while recovering from my surgery. But Bridget & Maryellen are very willing to be on-call for me and even Jim/Kathleen are offering their place for me to come over."
        },
        {
          "text": "He spent the weekend on call and couldn't fully relax."
        },
        {
          "text": "Get the surgeon on call in here right now!"
        },
        {
          "text": "Who is on call tonight?"
        }
      ],
      "glosses": [
        "Available to be summoned."
      ],
      "id": "en-on_call-en-prep_phrase-O9IL1ywQ",
      "links": [
        [
          "Available",
          "available"
        ],
        [
          "summon",
          "summon"
        ]
      ],
      "related": [
        {
          "word": "at someone's beck and call"
        },
        {
          "word": "on duty"
        }
      ],
      "synonyms": [
        {
          "tags": [
            "adjective"
          ],
          "word": "on-call"
        },
        {
          "word": "at call"
        }
      ],
      "translations": [
        {
          "code": "ca",
          "lang": "Catalan",
          "sense": "available to be summoned",
          "word": "de guàrdia"
        },
        {
          "code": "da",
          "lang": "Danish",
          "sense": "available to be summoned",
          "word": "på tilkaldevagt"
        },
        {
          "code": "fi",
          "english": "verb; to be on call",
          "lang": "Finnish",
          "sense": "available to be summoned",
          "word": "päivystää"
        },
        {
          "code": "fr",
          "lang": "French",
          "sense": "available to be summoned",
          "word": "de garde"
        },
        {
          "code": "de",
          "lang": "German",
          "sense": "available to be summoned",
          "word": "Bereitschaftsdienst habend"
        },
        {
          "code": "de",
          "lang": "German",
          "sense": "available to be summoned",
          "word": "im Bereitschaftsdienst"
        },
        {
          "code": "de",
          "english": "to be on call",
          "lang": "German",
          "sense": "available to be summoned",
          "word": "Bereitschaft haben"
        },
        {
          "code": "hu",
          "lang": "Hungarian",
          "sense": "available to be summoned",
          "word": "készenlétben"
        },
        {
          "code": "hu",
          "lang": "Hungarian",
          "sense": "available to be summoned",
          "word": "ügyeletben"
        },
        {
          "code": "hu",
          "lang": "Hungarian",
          "sense": "available to be summoned",
          "word": "készültségben"
        },
        {
          "code": "pt",
          "lang": "Portuguese",
          "sense": "available to be summoned",
          "word": "de sobreaviso"
        },
        {
          "code": "pt",
          "lang": "Portuguese",
          "sense": "available to be summoned",
          "word": "de plantão"
        },
        {
          "code": "sh",
          "lang": "Serbo-Croatian",
          "sense": "available to be summoned",
          "word": "dežuran"
        },
        {
          "code": "es",
          "lang": "Spanish",
          "sense": "available to be summoned",
          "word": "de guardia"
        },
        {
          "code": "sv",
          "lang": "Swedish",
          "sense": "available to be summoned",
          "word": "på jour"
        },
        {
          "code": "sv",
          "lang": "Swedish",
          "sense": "available to be summoned",
          "tags": [
            "common-gender"
          ],
          "word": "bakjour"
        }
      ]
    }
  ],
  "word": "on call"
}

{
  "derived": [
    {
      "word": "on firecall"
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "prepositional phrase",
        "head": ""
      },
      "expansion": "on call",
      "name": "head"
    },
    {
      "args": {},
      "expansion": "on call",
      "name": "en-PP"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "prep_phrase",
  "related": [
    {
      "word": "at someone's beck and call"
    },
    {
      "word": "on duty"
    }
  ],
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English prepositional phrases"
      ],
      "examples": [
        {
          "text": "1984-1986, Lou Sullivan, personal diary, quoted in 2019, Ellis Martin, Zach Ozma (editors), We Both Laughed In Pleasure\nKnow I cannot rely on him to do anything for me while recovering from my surgery. But Bridget & Maryellen are very willing to be on-call for me and even Jim/Kathleen are offering their place for me to come over."
        },
        {
          "text": "He spent the weekend on call and couldn't fully relax."
        },
        {
          "text": "Get the surgeon on call in here right now!"
        },
        {
          "text": "Who is on call tonight?"
        }
      ],
      "glosses": [
        "Available to be summoned."
      ],
      "links": [
        [
          "Available",
          "available"
        ],
        [
          "summon",
          "summon"
        ]
      ]
    }
  ],
  "synonyms": [
    {
      "tags": [
        "adjective"
      ],
      "word": "on-call"
    },
    {
      "word": "at call"
    }
  ],
  "translations": [
    {
      "code": "ca",
      "lang": "Catalan",
      "sense": "available to be summoned",
      "word": "de guàrdia"
    },
    {
      "code": "da",
      "lang": "Danish",
      "sense": "available to be summoned",
      "word": "på tilkaldevagt"
    },
    {
      "code": "fi",
      "english": "verb; to be on call",
      "lang": "Finnish",
      "sense": "available to be summoned",
      "word": "päivystää"
    },
    {
      "code": "fr",
      "lang": "French",
      "sense": "available to be summoned",
      "word": "de garde"
    },
    {
      "code": "de",
      "lang": "German",
      "sense": "available to be summoned",
      "word": "Bereitschaftsdienst habend"
    },
    {
      "code": "de",
      "lang": "German",
      "sense": "available to be summoned",
      "word": "im Bereitschaftsdienst"
    },
    {
      "code": "de",
      "english": "to be on call",
      "lang": "German",
      "sense": "available to be summoned",
      "word": "Bereitschaft haben"
    },
    {
      "code": "hu",
      "lang": "Hungarian",
      "sense": "available to be summoned",
      "word": "készenlétben"
    },
    {
      "code": "hu",
      "lang": "Hungarian",
      "sense": "available to be summoned",
      "word": "ügyeletben"
    },
    {
      "code": "hu",
      "lang": "Hungarian",
      "sense": "available to be summoned",
      "word": "készültségben"
    },
    {
      "code": "pt",
      "lang": "Portuguese",
      "sense": "available to be summoned",
      "word": "de sobreaviso"
    },
    {
      "code": "pt",
      "lang": "Portuguese",
      "sense": "available to be summoned",
      "word": "de plantão"
    },
    {
      "code": "sh",
      "lang": "Serbo-Croatian",
      "sense": "available to be summoned",
      "word": "dežuran"
    },
    {
      "code": "es",
      "lang": "Spanish",
      "sense": "available to be summoned",
      "word": "de guardia"
    },
    {
      "code": "sv",
      "lang": "Swedish",
      "sense": "available to be summoned",
      "word": "på jour"
    },
    {
      "code": "sv",
      "lang": "Swedish",
      "sense": "available to be summoned",
      "tags": [
        "common-gender"
      ],
      "word": "bakjour"
    }
  ],
  "word": "on call"
}