"knock box" meaning in English

{
  "forms": [
    {
      "form": "knock boxes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "knock box (plural knock boxes)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with topic categories using raw markup",
          "parents": [
            "Entries with topic categories using raw markup",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms with non-redundant non-automated sortkeys",
          "parents": [
            "Terms with non-redundant non-automated sortkeys",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Coffee",
          "orig": "en:Coffee",
          "parents": [
            "Beverages",
            "Drinking",
            "Food and drink",
            "Liquids",
            "Human behaviour",
            "All topics",
            "Matter",
            "Human",
            "Fundamental",
            "Chemistry",
            "Nature",
            "Sciences"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Containers",
          "orig": "en:Containers",
          "parents": [
            "Tools",
            "Technology",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A small container usually provided with a bar used to empty espresso grounds by pounding a portafilter against the sides or the bar."
      ],
      "id": "en-knock_box-en-noun-qJ9CYnoL",
      "links": [
        [
          "espresso",
          "espresso"
        ],
        [
          "grounds",
          "grounds"
        ],
        [
          "portafilter",
          "portafilter"
        ]
      ],
      "synonyms": [
        {
          "word": "knockbox"
        }
      ]
    }
  ],
  "word": "knock box"
}

{
  "forms": [
    {
      "form": "knock boxes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "knock box (plural knock boxes)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English entries with topic categories using raw markup",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with non-redundant non-automated sortkeys",
        "en:Coffee",
        "en:Containers"
      ],
      "glosses": [
        "A small container usually provided with a bar used to empty espresso grounds by pounding a portafilter against the sides or the bar."
      ],
      "links": [
        [
          "espresso",
          "espresso"
        ],
        [
          "grounds",
          "grounds"
        ],
        [
          "portafilter",
          "portafilter"
        ]
      ]
    }
  ],
  "synonyms": [
    {
      "word": "knockbox"
    }
  ],
  "word": "knock box"
}