"French letter" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "French",
        "3": "letter"
      },
      "expansion": "French + letter",
      "name": "compound"
    }
  ],
  "etymology_text": "From French + letter. Compare earlier French pox, French-sick (“syphilis”), or later French safe, French tickler (“condom”), or French kiss. Attested from the 19th century.",
  "forms": [
    {
      "form": "French letters",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "French letter (plural French letters)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "British English",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Commonwealth English",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English euphemisms",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Irish English",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Birth control",
          "orig": "en:Birth control",
          "parents": [
            "Pregnancy",
            "Sex",
            "Body",
            "Gynaecology",
            "All topics",
            "Reproduction",
            "Female",
            "Medicine",
            "Fundamental",
            "Life",
            "Gender",
            "Biology",
            "Healthcare",
            "Nature",
            "Psychology",
            "Sociology",
            "Sciences",
            "Health",
            "Social sciences",
            "Society"
          ],
          "source": "w"
        }
      ],
      "derived": [
        {
          "word": "Frenchie"
        }
      ],
      "examples": [
        {
          "ref": "1984, Leslie Thomas, In my Wildest Dreams, page 289:",
          "text": "‘So you’re fifteen – and you know the function of a “French letter”? You are familiar with its use?’\n‘I know what it’s for, sir, yes.’",
          "type": "quote"
        },
        {
          "ref": "2012, Courtney Milan, A Kiss for Midwinter, page 80:",
          "text": "“I suppose it’s too much to hope that you have a question about gonorrhea. Those questions are so much easier to answer.”[…]\n“I was going to ask about what you said earlier. That you’d... that you’d... not used a French letter in eighteen months.”",
          "type": "quote"
        }
      ],
      "glosses": [
        "A condom."
      ],
      "id": "en-French_letter-en-noun-Tlq6fyX7",
      "links": [
        [
          "condom",
          "condom"
        ]
      ],
      "raw_glosses": [
        "(UK, Ireland, Commonwealth, dated, euphemistic) A condom."
      ],
      "synonyms": [
        {
          "word": "condom"
        }
      ],
      "tags": [
        "Commonwealth",
        "Ireland",
        "UK",
        "dated",
        "euphemistic"
      ]
    }
  ],
  "word": "French letter"
}

{
  "derived": [
    {
      "word": "Frenchie"
    }
  ],
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "French",
        "3": "letter"
      },
      "expansion": "French + letter",
      "name": "compound"
    }
  ],
  "etymology_text": "From French + letter. Compare earlier French pox, French-sick (“syphilis”), or later French safe, French tickler (“condom”), or French kiss. Attested from the 19th century.",
  "forms": [
    {
      "form": "French letters",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "French letter (plural French letters)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "British English",
        "Commonwealth English",
        "English compound terms",
        "English countable nouns",
        "English dated terms",
        "English entries with incorrect language header",
        "English euphemisms",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations",
        "Irish English",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Birth control"
      ],
      "examples": [
        {
          "ref": "1984, Leslie Thomas, In my Wildest Dreams, page 289:",
          "text": "‘So you’re fifteen – and you know the function of a “French letter”? You are familiar with its use?’\n‘I know what it’s for, sir, yes.’",
          "type": "quote"
        },
        {
          "ref": "2012, Courtney Milan, A Kiss for Midwinter, page 80:",
          "text": "“I suppose it’s too much to hope that you have a question about gonorrhea. Those questions are so much easier to answer.”[…]\n“I was going to ask about what you said earlier. That you’d... that you’d... not used a French letter in eighteen months.”",
          "type": "quote"
        }
      ],
      "glosses": [
        "A condom."
      ],
      "links": [
        [
          "condom",
          "condom"
        ]
      ],
      "raw_glosses": [
        "(UK, Ireland, Commonwealth, dated, euphemistic) A condom."
      ],
      "synonyms": [
        {
          "word": "condom"
        }
      ],
      "tags": [
        "Commonwealth",
        "Ireland",
        "UK",
        "dated",
        "euphemistic"
      ]
    }
  ],
  "word": "French letter"
}