"εφ" meaning in Greek

{
  "forms": [
    {
      "form": "ef",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "el",
        "2": "symbol"
      },
      "expansion": "εφ • (ef)",
      "name": "head"
    }
  ],
  "lang": "Greek",
  "lang_code": "el",
  "pos": "symbol",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Greek entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Greek symbols",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "el",
          "name": "Trigonometry",
          "orig": "el:Trigonometry",
          "parents": [
            "Mathematics",
            "Formal sciences",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "tan, the symbol for εφαπτομένη the trigonometric function tangent"
      ],
      "id": "en-εφ-el-symbol-kHu69pVX",
      "links": [
        [
          "trigonometry",
          "trigonometry"
        ],
        [
          "tan",
          "tan"
        ],
        [
          "εφαπτομένη",
          "εφαπτομένη"
        ],
        [
          "trigonometric function",
          "trigonometric function"
        ],
        [
          "tangent",
          "tangent"
        ]
      ],
      "raw_glosses": [
        "(trigonometry) tan, the symbol for εφαπτομένη the trigonometric function tangent"
      ],
      "related": [
        {
          "english": "Trigonometric functions",
          "word": "Τριγωνομετρικές συναρτήσεις •"
        },
        {
          "word": "ημ"
        },
        {
          "english": "sin, sine",
          "roman": "im, imítono",
          "tags": [
            "neuter"
          ],
          "word": "ημίτονο"
        },
        {
          "word": "συν"
        },
        {
          "english": "cos, cosine",
          "roman": "syn, synimítono",
          "tags": [
            "neuter"
          ],
          "word": "συνημίτονο"
        },
        {
          "english": "tan, tangent",
          "roman": "ef, efaptoméni",
          "tags": [
            "feminine"
          ],
          "word": "εφαπτομένη"
        },
        {
          "word": "σφ"
        },
        {
          "english": "cot, cotangent",
          "roman": "sf, synefaptoméni",
          "tags": [
            "feminine"
          ],
          "word": "συνεφαπτομένη"
        },
        {
          "word": "στεμ"
        },
        {
          "english": "cosec, cosecant",
          "roman": "syntémnousa",
          "tags": [
            "feminine",
            "stem"
          ],
          "word": "συντέμνουσα"
        },
        {
          "word": "τεμ"
        },
        {
          "english": "sec, secant",
          "roman": "tem, témnousa",
          "tags": [
            "feminine"
          ],
          "word": "τέμνουσα"
        }
      ],
      "topics": [
        "mathematics",
        "sciences",
        "trigonometry"
      ]
    }
  ],
  "word": "εφ"
}

{
  "forms": [
    {
      "form": "ef",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "el",
        "2": "symbol"
      },
      "expansion": "εφ • (ef)",
      "name": "head"
    }
  ],
  "lang": "Greek",
  "lang_code": "el",
  "pos": "symbol",
  "related": [
    {
      "english": "Trigonometric functions",
      "word": "Τριγωνομετρικές συναρτήσεις •"
    },
    {
      "word": "ημ"
    },
    {
      "english": "sin, sine",
      "roman": "im, imítono",
      "tags": [
        "neuter"
      ],
      "word": "ημίτονο"
    },
    {
      "word": "συν"
    },
    {
      "english": "cos, cosine",
      "roman": "syn, synimítono",
      "tags": [
        "neuter"
      ],
      "word": "συνημίτονο"
    },
    {
      "english": "tan, tangent",
      "roman": "ef, efaptoméni",
      "tags": [
        "feminine"
      ],
      "word": "εφαπτομένη"
    },
    {
      "word": "σφ"
    },
    {
      "english": "cot, cotangent",
      "roman": "sf, synefaptoméni",
      "tags": [
        "feminine"
      ],
      "word": "συνεφαπτομένη"
    },
    {
      "word": "στεμ"
    },
    {
      "english": "cosec, cosecant",
      "roman": "syntémnousa",
      "tags": [
        "feminine",
        "stem"
      ],
      "word": "συντέμνουσα"
    },
    {
      "word": "τεμ"
    },
    {
      "english": "sec, secant",
      "roman": "tem, témnousa",
      "tags": [
        "feminine"
      ],
      "word": "τέμνουσα"
    }
  ],
  "senses": [
    {
      "categories": [
        "Greek entries with incorrect language header",
        "Greek lemmas",
        "Greek symbols",
        "el:Trigonometry"
      ],
      "glosses": [
        "tan, the symbol for εφαπτομένη the trigonometric function tangent"
      ],
      "links": [
        [
          "trigonometry",
          "trigonometry"
        ],
        [
          "tan",
          "tan"
        ],
        [
          "εφαπτομένη",
          "εφαπτομένη"
        ],
        [
          "trigonometric function",
          "trigonometric function"
        ],
        [
          "tangent",
          "tangent"
        ]
      ],
      "raw_glosses": [
        "(trigonometry) tan, the symbol for εφαπτομένη the trigonometric function tangent"
      ],
      "topics": [
        "mathematics",
        "sciences",
        "trigonometry"
      ]
    }
  ],
  "word": "εφ"
}