"a lo mejor" meaning in Spanish

{
  "etymology_text": "Maybe from \"en el mejor de los casos\": in the best case.",
  "head_templates": [
    {
      "args": {},
      "expansion": "a lo mejor",
      "name": "es-adv"
    }
  ],
  "hyphenation": [
    "a"
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Spanish entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "maybe, perhaps"
      ],
      "id": "en-a_lo_mejor-es-adv-pHbKE8M2",
      "links": [
        [
          "maybe",
          "maybe"
        ],
        [
          "perhaps",
          "perhaps"
        ]
      ],
      "raw_glosses": [
        "(idiomatic) maybe, perhaps"
      ],
      "related": [
        {
          "word": "posiblemente"
        }
      ],
      "synonyms": [
        {
          "word": "quizá"
        },
        {
          "word": "quizás"
        },
        {
          "word": "tal vez"
        },
        {
          "tags": [
            "Mexico"
          ],
          "word": "a la mejor"
        }
      ],
      "tags": [
        "idiomatic"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/a lo meˈxoɾ/"
    },
    {
      "ipa": "[a lo meˈxoɾ]"
    }
  ],
  "word": "a lo mejor"
}

{
  "etymology_text": "Maybe from \"en el mejor de los casos\": in the best case.",
  "head_templates": [
    {
      "args": {},
      "expansion": "a lo mejor",
      "name": "es-adv"
    }
  ],
  "hyphenation": [
    "a"
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "adv",
  "related": [
    {
      "word": "posiblemente"
    }
  ],
  "senses": [
    {
      "categories": [
        "Spanish adverbs",
        "Spanish entries with incorrect language header",
        "Spanish idioms",
        "Spanish lemmas",
        "Spanish multiword terms",
        "Spanish terms with IPA pronunciation"
      ],
      "glosses": [
        "maybe, perhaps"
      ],
      "links": [
        [
          "maybe",
          "maybe"
        ],
        [
          "perhaps",
          "perhaps"
        ]
      ],
      "raw_glosses": [
        "(idiomatic) maybe, perhaps"
      ],
      "synonyms": [
        {
          "word": "quizá"
        },
        {
          "word": "quizás"
        },
        {
          "word": "tal vez"
        }
      ],
      "tags": [
        "idiomatic"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/a lo meˈxoɾ/"
    },
    {
      "ipa": "[a lo meˈxoɾ]"
    }
  ],
  "synonyms": [
    {
      "tags": [
        "Mexico"
      ],
      "word": "a la mejor"
    }
  ],
  "word": "a lo mejor"
}