IPA: /ˈɔːɡənaɪzə/
KK: /ˈɔrɡəˌnaɪzər/
A person who arranges or coordinates events, activities, or tasks.
The organiser planned a fantastic conference for all the attendees.
Organiser → It is formed from "organ" (from Greek "organon", meaning tool or instrument) and "-iser" (a suffix used to indicate a person who performs a specific action). The word "organiser" refers to a person who arranges or coordinates activities or events, acting as a tool for organization.
Think of someone who acts as a 'tool' ('organ') to help 'organize' things — that's what an organiser does.