"needle exchange" meaning in English

{
  "forms": [
    {
      "form": "needle exchanges",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "~"
      },
      "expansion": "needle exchange (countable and uncountable, plural needle exchanges)",
      "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"
        }
      ],
      "glosses": [
        "A place or service that allows intravenous drug users to obtain new hypodermic needles at little or no cost, often in exchange for used ones."
      ],
      "id": "en-needle_exchange-en-noun-mGXH0kNO",
      "links": [
        [
          "place",
          "place"
        ],
        [
          "service",
          "service"
        ],
        [
          "intravenous",
          "intravenous"
        ],
        [
          "drug",
          "drug"
        ],
        [
          "obtain",
          "obtain"
        ],
        [
          "hypodermic needle",
          "hypodermic needle"
        ],
        [
          "exchange",
          "exchange"
        ]
      ],
      "related": [
        {
          "word": "needle sharing"
        }
      ],
      "synonyms": [
        {
          "word": "needle-exchange"
        }
      ],
      "tags": [
        "countable",
        "uncountable"
      ],
      "wikipedia": [
        "needle exchange programme"
      ]
    }
  ],
  "word": "needle exchange"
}

{
  "forms": [
    {
      "form": "needle exchanges",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "~"
      },
      "expansion": "needle exchange (countable and uncountable, plural needle exchanges)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "needle sharing"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English uncountable nouns"
      ],
      "glosses": [
        "A place or service that allows intravenous drug users to obtain new hypodermic needles at little or no cost, often in exchange for used ones."
      ],
      "links": [
        [
          "place",
          "place"
        ],
        [
          "service",
          "service"
        ],
        [
          "intravenous",
          "intravenous"
        ],
        [
          "drug",
          "drug"
        ],
        [
          "obtain",
          "obtain"
        ],
        [
          "hypodermic needle",
          "hypodermic needle"
        ],
        [
          "exchange",
          "exchange"
        ]
      ],
      "tags": [
        "countable",
        "uncountable"
      ],
      "wikipedia": [
        "needle exchange programme"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "needle-exchange"
    }
  ],
  "word": "needle exchange"
}