"polyphthong" meaning in English

{
  "forms": [
    {
      "form": "polyphthongs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "polyphthong (plural polyphthongs)",
      "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": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Phonetics",
          "orig": "en:Phonetics",
          "parents": [
            "Linguistics",
            "Language",
            "Social sciences",
            "Communication",
            "Sciences",
            "Society",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1973, Journal of the Chinese Language Teachers Association, page 65:",
          "text": "The teacher who uses Pinyin without knowing about such things as the place of the tone symbol in the case of polyphthong finals is merely incompetent but the teacher who supports the student in developing false notions about the language norm by adopting a systematically casual attitude to its technical aspects, can cause much greater harm.",
          "type": "quote"
        },
        {
          "ref": "1997, Ilse Lehiste, Jaan Ross, Estonian Prosody: Papers from a Symposium:",
          "text": "A syllable is short when ending in a short monophthong or in a short polyphthong; a syllable is long when ending in a consonant or in a long monophthong or a long polyphthong.",
          "type": "quote"
        },
        {
          "ref": "2012, Kingsley Amis, Memoirs, →ISBN, page 292:",
          "text": "With small preliminary he told Russ and me something like the following - I have normalised his speech in the interests of general sanity, though his polyphthongs ('hayyut' for 'hat', 'bawun' for 'born', etc.) were of the rarest quality.",
          "type": "quote"
        }
      ],
      "glosses": [
        "A phoneme that begins with the sound of one vowel or semivowel and transitions through one or more other (semi)vowel sounds."
      ],
      "id": "en-polyphthong-en-noun-xy560T6A",
      "links": [
        [
          "phonetics",
          "phonetics"
        ],
        [
          "phoneme",
          "phoneme"
        ],
        [
          "vowel",
          "vowel"
        ],
        [
          "semivowel",
          "semivowel"
        ]
      ],
      "raw_glosses": [
        "(phonetics) A phoneme that begins with the sound of one vowel or semivowel and transitions through one or more other (semi)vowel sounds."
      ],
      "related": [
        {
          "word": "diphthong"
        }
      ],
      "topics": [
        "human-sciences",
        "linguistics",
        "phonetics",
        "phonology",
        "sciences"
      ]
    }
  ],
  "word": "polyphthong"
}

{
  "forms": [
    {
      "form": "polyphthongs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "polyphthong (plural polyphthongs)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "diphthong"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English nouns",
        "English terms with quotations",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Phonetics"
      ],
      "examples": [
        {
          "ref": "1973, Journal of the Chinese Language Teachers Association, page 65:",
          "text": "The teacher who uses Pinyin without knowing about such things as the place of the tone symbol in the case of polyphthong finals is merely incompetent but the teacher who supports the student in developing false notions about the language norm by adopting a systematically casual attitude to its technical aspects, can cause much greater harm.",
          "type": "quote"
        },
        {
          "ref": "1997, Ilse Lehiste, Jaan Ross, Estonian Prosody: Papers from a Symposium:",
          "text": "A syllable is short when ending in a short monophthong or in a short polyphthong; a syllable is long when ending in a consonant or in a long monophthong or a long polyphthong.",
          "type": "quote"
        },
        {
          "ref": "2012, Kingsley Amis, Memoirs, →ISBN, page 292:",
          "text": "With small preliminary he told Russ and me something like the following - I have normalised his speech in the interests of general sanity, though his polyphthongs ('hayyut' for 'hat', 'bawun' for 'born', etc.) were of the rarest quality.",
          "type": "quote"
        }
      ],
      "glosses": [
        "A phoneme that begins with the sound of one vowel or semivowel and transitions through one or more other (semi)vowel sounds."
      ],
      "links": [
        [
          "phonetics",
          "phonetics"
        ],
        [
          "phoneme",
          "phoneme"
        ],
        [
          "vowel",
          "vowel"
        ],
        [
          "semivowel",
          "semivowel"
        ]
      ],
      "raw_glosses": [
        "(phonetics) A phoneme that begins with the sound of one vowel or semivowel and transitions through one or more other (semi)vowel sounds."
      ],
      "topics": [
        "human-sciences",
        "linguistics",
        "phonetics",
        "phonology",
        "sciences"
      ]
    }
  ],
  "word": "polyphthong"
}