The entity that operates the technical infrastructure for a top-level domain. They maintain the authoritative nameservers, process registrar requests via EPP, and control who can register under that TLD.
Registries are separate from registrars. A registry owns the zone file; registrars sell domains to you. ICANN accredits registrars, but registries answer to ICANN and the sponsoring organization (if any). For example: Verisign runs .com, Nominet runs .uk, the Internet Foundation runs .is.
This separation matters because registry policy determines what's actually allowed. Some registries (like .is, .ch, .ws) are notably hostile to takedown pressure. Others (.com, .org) comply aggressively with DMCA and court orders. A few (like .ai, .io) are pure cash registers with minimal oversight.
Bunkerdomains works with registries that don't log WHOIS queries, don't forward abuse complaints to registrants without cause, and don't preemptively nuke domains over unproven allegations. We choose registries, not just registrars.