Do a site command search and add either a normal query after it or another search operator after it, for example [site:seroundtable.com inurl:algorithm] or [site:seroundtable.com algorithm] or something similar and Google won't only just show you results from this site but will also offer you up the definition of "algorithm" and the knowledge panel on it.
Here is a screen shot:
Glenn Gabe posted about this on Twitter and thought it was interesting. It is interesting but this is Google probably simply not maintaining how the site commands return results. Google is always telling webmasters not to focus on site commands. They are not a popular search feature, even though people like you and me use it all the time - the general searcher does not.
Interesting, site commands combined with text or additional commands (like inurl) are yielding definitions and knowledge graph results. I guess Google's algorithms are trying to be extra helpful here. :) @rustybrick @JohnMu pic.twitter.com/fpOEch7Dim
— Glenn Gabe (@glenngabe) June 6, 2018
Google didn't always show knowledge panels and definitions when you searched Google like this.
Forum discussion at Twitter.
Update: Google is investigating:
This particular search is pretty weird. But hadn't realized dictionary was trigger for things like site: -- I'll pass this on.
— Danny Sullivan (@dannysullivan) June 12, 2018
