"-аар" meaning in Mongol

{
  "categories": [
    {
      "kind": "other",
      "name": "Particules en mongol",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Mongol",
      "orig": "mongol",
      "parents": [],
      "source": "w"
    }
  ],
  "lang": "Mongol",
  "lang_code": "mn",
  "pos": "particle",
  "pos_title": "Particule",
  "senses": [
    {
      "glosses": [
        "Dans, postposition indiquant la localité à l'intérieur d'un lieu."
      ],
      "id": "fr--аар-mn-particle-oo~9fbqM"
    },
    {
      "glosses": [
        "À, postposition indiquant la direction."
      ],
      "id": "fr--аар-mn-particle-MYgb3izD"
    }
  ],
  "synonyms": [
    {
      "word": "дотор"
    },
    {
      "word": "дээр"
    }
  ],
  "word": "-аар"
}

{
  "categories": [
    "Particules en mongol",
    "mongol"
  ],
  "lang": "Mongol",
  "lang_code": "mn",
  "pos": "particle",
  "pos_title": "Particule",
  "senses": [
    {
      "glosses": [
        "Dans, postposition indiquant la localité à l'intérieur d'un lieu."
      ]
    },
    {
      "glosses": [
        "À, postposition indiquant la direction."
      ]
    }
  ],
  "synonyms": [
    {
      "word": "дотор"
    },
    {
      "word": "дээр"
    }
  ],
  "word": "-аар"
}