"arctan" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "arc",
        "3": "tan"
      },
      "expansion": "arc- + tan",
      "name": "prefix"
    }
  ],
  "etymology_text": "From arc- + tan.",
  "forms": [
    {
      "form": "arctans",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "arctan (plural arctans)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "arctangent"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
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          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms prefixed with arc-",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Trigonometric functions",
          "orig": "en:Trigonometric functions",
          "parents": [
            "Circle",
            "Functions",
            "Trigonometry",
            "Curves",
            "Algebra",
            "Calculus",
            "Geometry",
            "Mathematical analysis",
            "Mathematics",
            "Shapes",
            "Formal sciences",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "tan (arctan 2/2)=1/ϕ"
        }
      ],
      "glosses": [
        "Abbreviation of arctangent."
      ],
      "id": "en-arctan-en-noun-VW6L53Vd",
      "links": [
        [
          "arctangent",
          "arctangent#English"
        ]
      ],
      "related": [
        {
          "word": "arcsin"
        },
        {
          "word": "arccos"
        }
      ],
      "synonyms": [
        {
          "word": "arctg"
        }
      ],
      "tags": [
        "abbreviation",
        "alt-of"
      ]
    }
  ],
  "word": "arctan"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "arc",
        "3": "tan"
      },
      "expansion": "arc- + tan",
      "name": "prefix"
    }
  ],
  "etymology_text": "From arc- + tan.",
  "forms": [
    {
      "form": "arctans",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "arctan (plural arctans)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "arcsin"
    },
    {
      "word": "arccos"
    }
  ],
  "senses": [
    {
      "alt_of": [
        {
          "word": "arctangent"
        }
      ],
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        "English abbreviations",
        "English countable nouns",
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        "Pages with 1 entry",
        "Pages with entries",
        "en:Trigonometric functions"
      ],
      "examples": [
        {
          "text": "tan (arctan 2/2)=1/ϕ"
        }
      ],
      "glosses": [
        "Abbreviation of arctangent."
      ],
      "links": [
        [
          "arctangent",
          "arctangent#English"
        ]
      ],
      "tags": [
        "abbreviation",
        "alt-of"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "arctg"
    }
  ],
  "word": "arctan"
}