IPA: /ˈspæmər/
KK: /ˈspæmɚ/
A person who sends unwanted or irrelevant messages, often in bulk, usually for advertising purposes.
The spammer flooded my inbox with advertisements for products I didn't want.
Spammer → The word is formed from 'spam' (originating from the brand name of a canned meat product, which became slang for unsolicited messages) and '-er' (meaning a person who). A spammer is a person who sends unsolicited messages, often in bulk.
Think of someone who sends out a lot of 'spam' messages — the '-er' just means a person who does that.