"cu" meaning in Spanish

{
  "forms": [
    {
      "form": "cus",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "cúes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "f",
        "2": "+",
        "pl2": "cúes"
      },
      "expansion": "cu f (plural cus or cúes)",
      "name": "es-noun"
    }
  ],
  "hyphenation": [
    "cu"
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "q"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "Spanish entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Spanish nouns with multiple plurals",
          "parents": [
            "Nouns with multiple plurals",
            "Nouns by inflection type",
            "Nouns",
            "Lemmas"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "es",
          "name": "Latin letter names",
          "orig": "es:Latin letter names",
          "parents": [
            "Letter names",
            "Letters, symbols, and punctuation",
            "Names",
            "Orthography",
            "All topics",
            "Proper nouns",
            "Terms by semantic function",
            "Writing",
            "Fundamental",
            "Nouns",
            "Human behaviour",
            "Language",
            "Lemmas",
            "Human",
            "Communication"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Name of the letter q"
      ],
      "id": "en-cu-es-noun-9dlBfsRo",
      "links": [
        [
          "q",
          "q#Spanish"
        ]
      ],
      "tags": [
        "alt-of",
        "feminine",
        "letter",
        "name"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ˈku/"
    },
    {
      "ipa": "[ˈku]"
    },
    {
      "rhymes": "-u"
    }
  ],
  "word": "cu"
}

{
  "forms": [
    {
      "form": "cus",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "cúes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "f",
        "2": "+",
        "pl2": "cúes"
      },
      "expansion": "cu f (plural cus or cúes)",
      "name": "es-noun"
    }
  ],
  "hyphenation": [
    "cu"
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "q"
        }
      ],
      "categories": [
        "Rhymes:Spanish/u",
        "Rhymes:Spanish/u/1 syllable",
        "Spanish 1-syllable words",
        "Spanish countable nouns",
        "Spanish entries with incorrect language header",
        "Spanish feminine nouns",
        "Spanish lemmas",
        "Spanish nouns",
        "Spanish nouns with multiple plurals",
        "Spanish terms with IPA pronunciation",
        "Spanish terms with audio links",
        "es:Latin letter names"
      ],
      "glosses": [
        "Name of the letter q"
      ],
      "links": [
        [
          "q",
          "q#Spanish"
        ]
      ],
      "tags": [
        "alt-of",
        "feminine",
        "letter",
        "name"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ˈku/"
    },
    {
      "ipa": "[ˈku]"
    },
    {
      "rhymes": "-u"
    }
  ],
  "word": "cu"
}