"null persistent" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "null",
        "3": "persistent"
      },
      "expansion": "null + persistent",
      "name": "compound"
    }
  ],
  "etymology_text": "From null + persistent.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "null persistent (not comparable)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "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": "Hebrew terms with redundant script codes",
          "parents": [
            "Terms with redundant script codes",
            "Entry maintenance"
          ],
          "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 Hebrew translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Mathematics",
          "orig": "en:Mathematics",
          "parents": [
            "Formal sciences",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "persistent with infinite expected return time."
      ],
      "id": "en-null_persistent-en-adj-ey4b2awl",
      "links": [
        [
          "mathematics",
          "mathematics"
        ],
        [
          "state",
          "state"
        ],
        [
          "persistent",
          "persistent"
        ]
      ],
      "qualifier": "stochastic processes",
      "raw_glosses": [
        "(mathematics, stochastic processes, of a state) persistent with infinite expected return time."
      ],
      "raw_tags": [
        "of a state"
      ],
      "synonyms": [
        {
          "sense": "math",
          "word": "null recurrent"
        }
      ],
      "tags": [
        "not-comparable"
      ],
      "topics": [
        "mathematics",
        "sciences"
      ],
      "translations": [
        {
          "code": "he",
          "lang": "Hebrew",
          "roman": "nishné éfes",
          "sense": "recurrent with finite expected return time",
          "word": "נשנה אפס"
        }
      ],
      "wikipedia": [
        "Markov_chain#Recurrence"
      ]
    }
  ],
  "word": "null persistent"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "null",
        "3": "persistent"
      },
      "expansion": "null + persistent",
      "name": "compound"
    }
  ],
  "etymology_text": "From null + persistent.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "null persistent (not comparable)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "English adjectives",
        "English compound terms",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English uncomparable adjectives",
        "Entries with translation boxes",
        "Hebrew terms with redundant script codes",
        "Pages with 1 entry",
        "Pages with entries",
        "Terms with Hebrew translations",
        "en:Mathematics"
      ],
      "glosses": [
        "persistent with infinite expected return time."
      ],
      "links": [
        [
          "mathematics",
          "mathematics"
        ],
        [
          "state",
          "state"
        ],
        [
          "persistent",
          "persistent"
        ]
      ],
      "qualifier": "stochastic processes",
      "raw_glosses": [
        "(mathematics, stochastic processes, of a state) persistent with infinite expected return time."
      ],
      "raw_tags": [
        "of a state"
      ],
      "tags": [
        "not-comparable"
      ],
      "topics": [
        "mathematics",
        "sciences"
      ],
      "wikipedia": [
        "Markov_chain#Recurrence"
      ]
    }
  ],
  "synonyms": [
    {
      "sense": "math",
      "word": "null recurrent"
    }
  ],
  "translations": [
    {
      "code": "he",
      "lang": "Hebrew",
      "roman": "nishné éfes",
      "sense": "recurrent with finite expected return time",
      "word": "נשנה אפס"
    }
  ],
  "word": "null persistent"
}