"for fear of" meaning in English

{
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "prepositional phrase"
      },
      "expansion": "for fear of",
      "name": "head"
    }
  ],
  "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"
        }
      ],
      "examples": [
        {
          "ref": "1960 March, “Motive Power Miscellany: Western Region”, in Trains Illustrated, page 184",
          "text": "[...] but in the damp conditions prevailing the driver sensibly was unwilling to attempt the climb up through Combe Down tunnel without help, for fear of slipping to a standstill in the unventilated bore, [...].",
          "type": "quotation"
        }
      ],
      "glosses": [
        "In order to try to prevent the risk of a particular thing happening."
      ],
      "id": "en-for_fear_of-en-prep_phrase-CM0ISH-D",
      "related": [
        {
          "word": "for fear that"
        }
      ]
    }
  ],
  "word": "for fear of"
}

{
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "prepositional phrase"
      },
      "expansion": "for fear of",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "prep_phrase",
  "related": [
    {
      "word": "for fear that"
    }
  ],
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English prepositional phrases",
        "English terms with quotations"
      ],
      "examples": [
        {
          "ref": "1960 March, “Motive Power Miscellany: Western Region”, in Trains Illustrated, page 184",
          "text": "[...] but in the damp conditions prevailing the driver sensibly was unwilling to attempt the climb up through Combe Down tunnel without help, for fear of slipping to a standstill in the unventilated bore, [...].",
          "type": "quotation"
        }
      ],
      "glosses": [
        "In order to try to prevent the risk of a particular thing happening."
      ]
    }
  ],
  "word": "for fear of"
}