Looking to compare json files for differences using the word part of the json file

I am parsing the JSON file into a javascript object just having trouble accessing the word in each object unsure how to go about doing it.
JSON file looks like this:

 "words": [
        {
            "word": "all",
            "start": 260.80997,
            "end": 260.90497,
            "confidence": 0.38183594,
            "punctuated_word": "All"
        },
        {
            "word": "right",
            "start": 260.90497,
            "end": 261,
            "confidence": 0.81152344,
            "punctuated_word": "right."
        },

I have tried using the dot operator and doing obj[key] but get undefined