"null morpheme" meaning in English

{
  "forms": [
    {
      "form": "null morphemes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "null morpheme (plural null morphemes)",
      "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": "Entries with translation boxes",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Catalan translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Finnish translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with French translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Hungarian translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Polish translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Russian translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Linguistics",
          "orig": "en:Linguistics",
          "parents": [
            "Language",
            "Social sciences",
            "Communication",
            "Sciences",
            "Society",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A morpheme that has no phonetic form, represented as the empty set symbol ∅."
      ],
      "id": "en-null_morpheme-en-noun-DDCIJDKn",
      "links": [
        [
          "linguistics",
          "linguistics"
        ],
        [
          "morpheme",
          "morpheme"
        ],
        [
          "∅",
          "∅"
        ]
      ],
      "raw_glosses": [
        "(linguistics) A morpheme that has no phonetic form, represented as the empty set symbol ∅."
      ],
      "synonyms": [
        {
          "word": "zero morph"
        },
        {
          "word": "zero morpheme"
        }
      ],
      "topics": [
        "human-sciences",
        "linguistics",
        "sciences"
      ],
      "translations": [
        {
          "code": "ca",
          "lang": "Catalan",
          "sense": "a morpheme that has no phonetic form",
          "tags": [
            "masculine"
          ],
          "word": "morfema zero"
        },
        {
          "code": "fi",
          "lang": "Finnish",
          "sense": "a morpheme that has no phonetic form",
          "word": "nollamorfeemi"
        },
        {
          "code": "fr",
          "lang": "French",
          "sense": "a morpheme that has no phonetic form",
          "tags": [
            "masculine"
          ],
          "word": "morphème zéro"
        },
        {
          "code": "fr",
          "lang": "French",
          "sense": "a morpheme that has no phonetic form",
          "tags": [
            "masculine"
          ],
          "word": "morphème nul"
        },
        {
          "code": "hu",
          "lang": "Hungarian",
          "sense": "a morpheme that has no phonetic form",
          "word": "zéró morféma"
        },
        {
          "code": "pl",
          "lang": "Polish",
          "sense": "a morpheme that has no phonetic form",
          "tags": [
            "masculine"
          ],
          "word": "zerowy morfem"
        },
        {
          "code": "ru",
          "lang": "Russian",
          "roman": "nulevaja morfema",
          "sense": "a morpheme that has no phonetic form",
          "word": "нулевая морфема"
        }
      ],
      "wikipedia": [
        "null morpheme"
      ]
    }
  ],
  "word": "null morpheme"
}

{
  "forms": [
    {
      "form": "null morphemes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "null morpheme (plural null morphemes)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Entries with translation boxes",
        "Pages with 1 entry",
        "Pages with entries",
        "Terms with Catalan translations",
        "Terms with Finnish translations",
        "Terms with French translations",
        "Terms with Hungarian translations",
        "Terms with Polish translations",
        "Terms with Russian translations",
        "en:Linguistics"
      ],
      "glosses": [
        "A morpheme that has no phonetic form, represented as the empty set symbol ∅."
      ],
      "links": [
        [
          "linguistics",
          "linguistics"
        ],
        [
          "morpheme",
          "morpheme"
        ],
        [
          "∅",
          "∅"
        ]
      ],
      "raw_glosses": [
        "(linguistics) A morpheme that has no phonetic form, represented as the empty set symbol ∅."
      ],
      "synonyms": [
        {
          "word": "zero morph"
        },
        {
          "word": "zero morpheme"
        }
      ],
      "topics": [
        "human-sciences",
        "linguistics",
        "sciences"
      ],
      "wikipedia": [
        "null morpheme"
      ]
    }
  ],
  "translations": [
    {
      "code": "ca",
      "lang": "Catalan",
      "sense": "a morpheme that has no phonetic form",
      "tags": [
        "masculine"
      ],
      "word": "morfema zero"
    },
    {
      "code": "fi",
      "lang": "Finnish",
      "sense": "a morpheme that has no phonetic form",
      "word": "nollamorfeemi"
    },
    {
      "code": "fr",
      "lang": "French",
      "sense": "a morpheme that has no phonetic form",
      "tags": [
        "masculine"
      ],
      "word": "morphème zéro"
    },
    {
      "code": "fr",
      "lang": "French",
      "sense": "a morpheme that has no phonetic form",
      "tags": [
        "masculine"
      ],
      "word": "morphème nul"
    },
    {
      "code": "hu",
      "lang": "Hungarian",
      "sense": "a morpheme that has no phonetic form",
      "word": "zéró morféma"
    },
    {
      "code": "pl",
      "lang": "Polish",
      "sense": "a morpheme that has no phonetic form",
      "tags": [
        "masculine"
      ],
      "word": "zerowy morfem"
    },
    {
      "code": "ru",
      "lang": "Russian",
      "roman": "nulevaja morfema",
      "sense": "a morpheme that has no phonetic form",
      "word": "нулевая морфема"
    }
  ],
  "word": "null morpheme"
}