If you had no time or interest to watch a long YouTube video but were only interested in seeing a short portion of it, where a particular word is mentioned, Invideo can help you. It is a light extension that once is installed, it is shown on the video page, on the right side of the video that you are currently watching. There you can type any search term that you want to find out in the video transcript and then hopefully get that same match inside it.
Once you have written the search term, you will then see the results next to your search. You may see several result items if that particular phrase is included more than once in the video. Then, you can click on any of the result items and have the chance to go to that particular sequence of the video and watch it.
There can words that you may not be able to find even though they may be mentioned or included in the video, as most of these captions are automatically generated and there can be some errors.
If searching for phrases inside YouTube videos is something of interest to you, then you can give Invideo a try.