IPA: /ˈsɜːrtɪfaɪər/
KK: /ˈsɜːrtɪfaɪər/
A person or organization that officially confirms or verifies something, often by providing a certificate.
The certifier issued a certificate to the company after reviewing their compliance with the standards.
Certifier → It is formed from "certus" (meaning certain or sure) and "-fier" (from Latin "facere", meaning to make or do). The word "certifier" means to make certain or to confirm something as true or valid.
Think of making something 'certain' ('certus') — that's why certifier means to confirm or validate.