"catch a crab" meaning in English

{
  "forms": [
    {
      "form": "catches a crab",
      "tags": [
        "present",
        "singular",
        "third-person"
      ]
    },
    {
      "form": "catching a crab",
      "tags": [
        "participle",
        "present"
      ]
    },
    {
      "form": "caught a crab",
      "tags": [
        "participle",
        "past"
      ]
    },
    {
      "form": "caught a crab",
      "tags": [
        "past"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "catch<,,caught> a crab"
      },
      "expansion": "catch a crab (third-person singular simple present catches a crab, present participle catching a crab, simple past and past participle caught a crab)",
      "name": "en-verb"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Rowing",
          "orig": "en:Rowing",
          "parents": [
            "Water sports",
            "Sports",
            "Human activity",
            "Human behaviour",
            "Human",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2014, Pip Harry, Head of the River, page 82",
          "text": "I blast off the first few strokes with all the anger and frustration I feel towards Rachel. It works against me. I catch a crab and totally lose it. The boat swings sideways and we have to easy oar or risk slamming into the bank.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "To strike the blade of the oar against the water when moving the oar back between power strokes."
      ],
      "id": "en-catch_a_crab-en-verb-0wwqNqoi",
      "links": [
        [
          "rowing",
          "rowing#Noun"
        ],
        [
          "strike",
          "strike"
        ],
        [
          "blade",
          "blade"
        ],
        [
          "oar",
          "oar"
        ],
        [
          "water",
          "water"
        ],
        [
          "power",
          "power"
        ],
        [
          "stroke",
          "stroke"
        ]
      ],
      "raw_glosses": [
        "(rowing) To strike the blade of the oar against the water when moving the oar back between power strokes."
      ],
      "topics": [
        "hobbies",
        "lifestyle",
        "rowing",
        "sports"
      ],
      "translations": [
        {
          "code": "mi",
          "lang": "Maori",
          "sense": "Translations",
          "word": "urupā"
        }
      ]
    }
  ],
  "word": "catch a crab"
}

{
  "forms": [
    {
      "form": "catches a crab",
      "tags": [
        "present",
        "singular",
        "third-person"
      ]
    },
    {
      "form": "catching a crab",
      "tags": [
        "participle",
        "present"
      ]
    },
    {
      "form": "caught a crab",
      "tags": [
        "participle",
        "past"
      ]
    },
    {
      "form": "caught a crab",
      "tags": [
        "past"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "catch<,,caught> a crab"
      },
      "expansion": "catch a crab (third-person singular simple present catches a crab, present participle catching a crab, simple past and past participle caught a crab)",
      "name": "en-verb"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English terms with quotations",
        "English verbs",
        "Quotation templates to be cleaned",
        "Translation table header lacks gloss",
        "en:Rowing"
      ],
      "examples": [
        {
          "ref": "2014, Pip Harry, Head of the River, page 82",
          "text": "I blast off the first few strokes with all the anger and frustration I feel towards Rachel. It works against me. I catch a crab and totally lose it. The boat swings sideways and we have to easy oar or risk slamming into the bank.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "To strike the blade of the oar against the water when moving the oar back between power strokes."
      ],
      "links": [
        [
          "rowing",
          "rowing#Noun"
        ],
        [
          "strike",
          "strike"
        ],
        [
          "blade",
          "blade"
        ],
        [
          "oar",
          "oar"
        ],
        [
          "water",
          "water"
        ],
        [
          "power",
          "power"
        ],
        [
          "stroke",
          "stroke"
        ]
      ],
      "raw_glosses": [
        "(rowing) To strike the blade of the oar against the water when moving the oar back between power strokes."
      ],
      "topics": [
        "hobbies",
        "lifestyle",
        "rowing",
        "sports"
      ]
    }
  ],
  "translations": [
    {
      "code": "mi",
      "lang": "Maori",
      "sense": "Translations",
      "word": "urupā"
    }
  ],
  "word": "catch a crab"
}