"hard-and-fast" meaning in English

{
  "etymology_text": ": hard-and-fast < → δείτε τις λέξεις hard και fast",
  "forms": [
    {
      "form": "hard-and-fast"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Ιδιωματισμοί (αγγλικά)",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "ο απαράβατος"
      ],
      "id": "el-hard-and-fast-en-adj-kLyRXKog",
      "raw_tags": [
        "ιδιωματισμός"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "strict"
    }
  ],
  "word": "hard-and-fast"
}

{
  "etymology_text": ": hard-and-fast < → δείτε τις λέξεις hard και fast",
  "forms": [
    {
      "form": "hard-and-fast"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "Ιδιωματισμοί (αγγλικά)"
      ],
      "glosses": [
        "ο απαράβατος"
      ],
      "raw_tags": [
        "ιδιωματισμός"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "strict"
    }
  ],
  "word": "hard-and-fast"
}