"fly under the radar" meaning in English

{
  "etymology_text": "From military contexts, where aircraft would fly low to avoid being detected by radar.",
  "forms": [
    {
      "form": "flies under the radar",
      "tags": [
        "present",
        "singular",
        "third-person"
      ]
    },
    {
      "form": "flying under the radar",
      "tags": [
        "participle",
        "present"
      ]
    },
    {
      "form": "flew under the radar",
      "tags": [
        "past"
      ]
    },
    {
      "form": "flown under the radar",
      "tags": [
        "participle",
        "past"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "fly<,,flew,flown> under the radar"
      },
      "expansion": "fly under the radar (third-person singular simple present flies under the radar, present participle flying under the radar, simple past flew under the radar, past participle flown under the radar)",
      "name": "en-verb"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "To go unnoticed, especially for a long period of time."
      ],
      "id": "en-fly_under_the_radar-en-verb-a~i~Tc-5",
      "links": [
        [
          "unnoticed",
          "unnoticed"
        ]
      ],
      "raw_glosses": [
        "(idiomatic) To go unnoticed, especially for a long period of time."
      ],
      "synonyms": [
        {
          "word": "slip under the radar"
        }
      ],
      "tags": [
        "idiomatic"
      ],
      "translations": [
        {
          "code": "fi",
          "lang": "Finnish",
          "sense": "to go unnoticed",
          "word": "piilotella"
        },
        {
          "code": "sv",
          "lang": "Swedish",
          "sense": "to go unnoticed",
          "word": "gå under radarn"
        },
        {
          "code": "sv",
          "lang": "Swedish",
          "sense": "to go unnoticed",
          "word": "flyga under radarn"
        }
      ]
    }
  ],
  "sounds": [
    {
      "audio": "en-au-fly under the radar.ogg",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/6/61/En-au-fly_under_the_radar.ogg/En-au-fly_under_the_radar.ogg.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/6/61/En-au-fly_under_the_radar.ogg",
      "tags": [
        "Australia"
      ],
      "text": "Audio (AU)"
    }
  ],
  "word": "fly under the radar"
}

{
  "etymology_text": "From military contexts, where aircraft would fly low to avoid being detected by radar.",
  "forms": [
    {
      "form": "flies under the radar",
      "tags": [
        "present",
        "singular",
        "third-person"
      ]
    },
    {
      "form": "flying under the radar",
      "tags": [
        "participle",
        "present"
      ]
    },
    {
      "form": "flew under the radar",
      "tags": [
        "past"
      ]
    },
    {
      "form": "flown under the radar",
      "tags": [
        "participle",
        "past"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "fly<,,flew,flown> under the radar"
      },
      "expansion": "fly under the radar (third-person singular simple present flies under the radar, present participle flying under the radar, simple past flew under the radar, past participle flown under the radar)",
      "name": "en-verb"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English idioms",
        "English lemmas",
        "English multiword terms",
        "English terms with audio links",
        "English verbs"
      ],
      "glosses": [
        "To go unnoticed, especially for a long period of time."
      ],
      "links": [
        [
          "unnoticed",
          "unnoticed"
        ]
      ],
      "raw_glosses": [
        "(idiomatic) To go unnoticed, especially for a long period of time."
      ],
      "tags": [
        "idiomatic"
      ]
    }
  ],
  "sounds": [
    {
      "audio": "en-au-fly under the radar.ogg",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/6/61/En-au-fly_under_the_radar.ogg/En-au-fly_under_the_radar.ogg.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/6/61/En-au-fly_under_the_radar.ogg",
      "tags": [
        "Australia"
      ],
      "text": "Audio (AU)"
    }
  ],
  "synonyms": [
    {
      "word": "slip under the radar"
    }
  ],
  "translations": [
    {
      "code": "fi",
      "lang": "Finnish",
      "sense": "to go unnoticed",
      "word": "piilotella"
    },
    {
      "code": "sv",
      "lang": "Swedish",
      "sense": "to go unnoticed",
      "word": "gå under radarn"
    },
    {
      "code": "sv",
      "lang": "Swedish",
      "sense": "to go unnoticed",
      "word": "flyga under radarn"
    }
  ],
  "word": "fly under the radar"
}