Multi-Domain Certificate
Noun · Security & Infosec
Definitions
A digital certificate that covers more than one domain name, usually by listing multiple subject alternative names in the certificate. Multi-domain certificates simplify some deployments but can increase blast radius if one private key protects many public-facing names.
In plain English: A certificate that is valid for multiple domain names.
Example: "The team split the giant multi-domain certificate after realizing a single key compromise would affect dozens of customer portals."