"fifth base" meaning in All languages combined

{
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "noun"
      },
      "expansion": "fifth base",
      "name": "head"
    }
  ],
  "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": [
        "Anal sex."
      ],
      "id": "en-fifth_base-en-noun-RwWNTn6Q",
      "links": [
        [
          "Anal sex",
          "anal sex"
        ]
      ],
      "raw_glosses": [
        "(colloquial) Anal sex."
      ],
      "tags": [
        "colloquial"
      ]
    }
  ],
  "word": "fifth base"
}

{
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "noun"
      },
      "expansion": "fifth base",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English colloquialisms",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns"
      ],
      "glosses": [
        "Anal sex."
      ],
      "links": [
        [
          "Anal sex",
          "anal sex"
        ]
      ],
      "raw_glosses": [
        "(colloquial) Anal sex."
      ],
      "tags": [
        "colloquial"
      ]
    }
  ],
  "word": "fifth base"
}