"not to say" meaning in English

{
  "head_templates": [
    {
      "args": {},
      "expansion": "not to say",
      "name": "en-con"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "conj",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "c. 1962, Jacqueline Shohet Kahanoff, “Wake of the Waves”, in Deborah A. Starr, Sasson Somekh, editors, Mongrels Or Marvels, Stanford University Press, published 2011, page 145",
          "text": "At first Marc was somewhat shocked, then he burst out laughing and finally came to the conclusion that actually it was all rather sad, not to say stupid.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Even; perhaps; almost."
      ],
      "id": "en-not_to_say-en-conj-u9npOGgG",
      "links": [
        [
          "Even",
          "even"
        ],
        [
          "perhaps",
          "perhaps"
        ],
        [
          "almost",
          "almost"
        ]
      ],
      "translations": [
        {
          "code": "nl",
          "lang": "Dutch",
          "sense": "even; perhaps; almost",
          "word": "om niet te zeggen"
        },
        {
          "code": "fr",
          "lang": "French",
          "sense": "even; perhaps; almost",
          "word": "pour ne pas dire"
        },
        {
          "code": "pl",
          "lang": "Polish",
          "sense": "even; perhaps; almost",
          "word": "żeby nie powiedzieć"
        }
      ]
    }
  ],
  "word": "not to say"
}

{
  "head_templates": [
    {
      "args": {},
      "expansion": "not to say",
      "name": "en-con"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "conj",
  "senses": [
    {
      "categories": [
        "English conjunctions",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English terms with quotations"
      ],
      "examples": [
        {
          "ref": "c. 1962, Jacqueline Shohet Kahanoff, “Wake of the Waves”, in Deborah A. Starr, Sasson Somekh, editors, Mongrels Or Marvels, Stanford University Press, published 2011, page 145",
          "text": "At first Marc was somewhat shocked, then he burst out laughing and finally came to the conclusion that actually it was all rather sad, not to say stupid.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Even; perhaps; almost."
      ],
      "links": [
        [
          "Even",
          "even"
        ],
        [
          "perhaps",
          "perhaps"
        ],
        [
          "almost",
          "almost"
        ]
      ]
    }
  ],
  "translations": [
    {
      "code": "nl",
      "lang": "Dutch",
      "sense": "even; perhaps; almost",
      "word": "om niet te zeggen"
    },
    {
      "code": "fr",
      "lang": "French",
      "sense": "even; perhaps; almost",
      "word": "pour ne pas dire"
    },
    {
      "code": "pl",
      "lang": "Polish",
      "sense": "even; perhaps; almost",
      "word": "żeby nie powiedzieć"
    }
  ],
  "word": "not to say"
}