Check a domain before buying
Availability and previous use are different checks.
Check availability
A domain search concerns ordering availability, not the previous website’s reputation. Missing search results alone do not prove a ban.
Review previous use
Look at archived pages, brand mentions and suspicious redirects. Public checks cannot guarantee the absence of all problems.
If you control the website
Verify ownership in Search Console and review Manual actions and Security issues. Fixes depend on the issue found. See also domain history.