"-fu" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "kung fu"
      },
      "expansion": "Back-formation from kung fu",
      "name": "back-form"
    }
  ],
  "etymology_text": "Back-formation from kung fu.",
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "suffixes"
      },
      "expansion": "-fu",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "suffix",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English back-formations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 4 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "derived": [
        {
          "word": "Google-fu"
        }
      ],
      "examples": [
        {
          "text": "Google + -fu → Google-fu",
          "type": "example"
        },
        {
          "text": "script + -fu → script-fu",
          "type": "example"
        },
        {
          "bold_text_offsets": [
            [
              9,
              12
            ]
          ],
          "text": "My Google-fu is weak!",
          "type": "example"
        },
        {
          "bold_text_offsets": [
            [
              19,
              22
            ]
          ],
          "text": "Aragorn uses Ranger-fu to figure out that Sam and Frodo have taken a boat.",
          "type": "example"
        }
      ],
      "glosses": [
        "Used to form nouns indicating expertise or mastery of specified skill or area of knowledge."
      ],
      "id": "en--fu-en-suffix-Ar3WbhvW",
      "links": [
        [
          "expertise",
          "expertise#English"
        ],
        [
          "mastery",
          "mastery#English"
        ]
      ],
      "raw_glosses": [
        "(slang) Used to form nouns indicating expertise or mastery of specified skill or area of knowledge."
      ],
      "related": [
        {
          "word": "fu"
        }
      ],
      "tags": [
        "morpheme",
        "slang"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/fuː/",
      "tags": [
        "UK"
      ]
    },
    {
      "rhymes": "-uː"
    },
    {
      "homophone": "foo"
    }
  ],
  "word": "-fu"
}

{
  "derived": [
    {
      "word": "Google-fu"
    }
  ],
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "kung fu"
      },
      "expansion": "Back-formation from kung fu",
      "name": "back-form"
    }
  ],
  "etymology_text": "Back-formation from kung fu.",
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "suffixes"
      },
      "expansion": "-fu",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "suffix",
  "related": [
    {
      "word": "fu"
    }
  ],
  "senses": [
    {
      "categories": [
        "English back-formations",
        "English entries with incorrect language header",
        "English lemmas",
        "English slang",
        "English suffixes",
        "English terms with homophones",
        "English terms with usage examples",
        "Pages with 4 entries",
        "Pages with entries",
        "Rhymes:English/uː"
      ],
      "examples": [
        {
          "text": "Google + -fu → Google-fu",
          "type": "example"
        },
        {
          "text": "script + -fu → script-fu",
          "type": "example"
        },
        {
          "bold_text_offsets": [
            [
              9,
              12
            ]
          ],
          "text": "My Google-fu is weak!",
          "type": "example"
        },
        {
          "bold_text_offsets": [
            [
              19,
              22
            ]
          ],
          "text": "Aragorn uses Ranger-fu to figure out that Sam and Frodo have taken a boat.",
          "type": "example"
        }
      ],
      "glosses": [
        "Used to form nouns indicating expertise or mastery of specified skill or area of knowledge."
      ],
      "links": [
        [
          "expertise",
          "expertise#English"
        ],
        [
          "mastery",
          "mastery#English"
        ]
      ],
      "raw_glosses": [
        "(slang) Used to form nouns indicating expertise or mastery of specified skill or area of knowledge."
      ],
      "tags": [
        "morpheme",
        "slang"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/fuː/",
      "tags": [
        "UK"
      ]
    },
    {
      "rhymes": "-uː"
    },
    {
      "homophone": "foo"
    }
  ],
  "word": "-fu"
}