"compulsory" meaning in English

{
  "forms": [
    {
      "form": "compulsory"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "examples": [
        {
          "text": "How many compulsory subjects do you have this semester?",
          "translation": "Πόσα υποχρεωτικά μαθήματα έχεις αυτό το εξάμηνο;"
        }
      ],
      "glosses": [
        "αναγκαστικός, υποχρεωτικός"
      ],
      "id": "el-compulsory-en-adj-9EVK~Cbi"
    }
  ],
  "synonyms": [
    {
      "word": "imperative"
    },
    {
      "word": "involuntary"
    },
    {
      "word": "mandatory"
    },
    {
      "word": "obligatory"
    },
    {
      "word": "required"
    }
  ],
  "word": "compulsory"
}

{
  "forms": [
    {
      "form": "compulsory"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "examples": [
        {
          "text": "How many compulsory subjects do you have this semester?",
          "translation": "Πόσα υποχρεωτικά μαθήματα έχεις αυτό το εξάμηνο;"
        }
      ],
      "glosses": [
        "αναγκαστικός, υποχρεωτικός"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "imperative"
    },
    {
      "word": "involuntary"
    },
    {
      "word": "mandatory"
    },
    {
      "word": "obligatory"
    },
    {
      "word": "required"
    }
  ],
  "word": "compulsory"
}