https://www.quora.com/Does-Quora-come-from-the-plural-versio...
https://www.google.com/search?client=firefox-b-d&q=%22Quora+...
Lexical gap refers to potential words that, with regards to the language morphology or semantic rules, could have been part of the language.
I think it's systematic gap that might apply to some of the domains you're squatting.
Now dead.
If you just check once a year, you likely won't find a good one. But if you check almost daily for years, you will eventually strike gold.
The one issue I did have was buying a domain on Namecheap auctions only to find it had been used very aggressively by spammers before going to auction. It made me think of the recent top HN post about how you could push a suspect domain to someone within a registrar and then implicate them without their knowledge. The Namecheap auction system happily let me buy the domain, but then as soon as it was in my account it got suspended and I got various emails from their security team about how many blocklists it was on and how I'd have to submit extensive documentation to get it unsuspended etc. Thankfully the support was helpful and now I check domains more thoroughly before I buy them...