"in saeculum" meaning in Latin

{
  "etymology_templates": [
    {
      "args": {
        "1": "into the age"
      },
      "expansion": "“into the age”",
      "name": "m-g"
    },
    {
      "args": {
        "1": "into the age"
      },
      "expansion": "Literally, “into the age”",
      "name": "lit"
    }
  ],
  "etymology_text": "Literally, “into the age”.",
  "head_templates": [
    {
      "args": {
        "1": "la",
        "2": "prepositional phrase"
      },
      "expansion": "in saeculum",
      "name": "head"
    }
  ],
  "lang": "Latin",
  "lang_code": "la",
  "pos": "prep_phrase",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Ecclesiastical Latin",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Latin 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"
        }
      ],
      "examples": [
        {
          "english": "Let the name of God be praised, from now and unto the ages.",
          "ref": "405 CE, Jerome, Vulgate Psalms.112.2",
          "text": "Sit nomen Domini benedictum ex nunc et usque in saeculum."
        }
      ],
      "glosses": [
        "forever"
      ],
      "id": "en-in_saeculum-la-prep_phrase-IHD3Jf8c",
      "links": [
        [
          "forever",
          "forever"
        ]
      ],
      "raw_glosses": [
        "(Ecclesiastical Latin) forever"
      ],
      "related": [
        {
          "word": "in saecula saeculōrum"
        }
      ],
      "tags": [
        "Ecclesiastical",
        "Latin"
      ]
    }
  ],
  "word": "in saeculum"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "into the age"
      },
      "expansion": "“into the age”",
      "name": "m-g"
    },
    {
      "args": {
        "1": "into the age"
      },
      "expansion": "Literally, “into the age”",
      "name": "lit"
    }
  ],
  "etymology_text": "Literally, “into the age”.",
  "head_templates": [
    {
      "args": {
        "1": "la",
        "2": "prepositional phrase"
      },
      "expansion": "in saeculum",
      "name": "head"
    }
  ],
  "lang": "Latin",
  "lang_code": "la",
  "pos": "prep_phrase",
  "related": [
    {
      "word": "in saecula saeculōrum"
    }
  ],
  "senses": [
    {
      "categories": [
        "Ecclesiastical Latin",
        "Latin entries with incorrect language header",
        "Latin lemmas",
        "Latin multiword terms",
        "Latin prepositional phrases",
        "Latin terms with quotations",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "examples": [
        {
          "english": "Let the name of God be praised, from now and unto the ages.",
          "ref": "405 CE, Jerome, Vulgate Psalms.112.2",
          "text": "Sit nomen Domini benedictum ex nunc et usque in saeculum."
        }
      ],
      "glosses": [
        "forever"
      ],
      "links": [
        [
          "forever",
          "forever"
        ]
      ],
      "raw_glosses": [
        "(Ecclesiastical Latin) forever"
      ],
      "tags": [
        "Ecclesiastical",
        "Latin"
      ]
    }
  ],
  "word": "in saeculum"
}