IPA: /ˈnjuːzˌlɛtə/
KK: /ˈnuzˌletər/
A small publication that provides news and information to a specific group of people.
I subscribed to the monthly newsletter to stay updated on local events.
Newsletter → It is formed from "news" (from Old English *news*, meaning new information) and "letter" (from Old French *lettre*, meaning a written message). The word "newsletter" refers to a written message that conveys new information.
Think of receiving a 'written message' ('letter') that shares 'new information' ('news') — that's what a newsletter is.