IPA: /ˈæməˌtʃɪrɪʃli/
KK: /ˈæmətʃərɪʃli/
In a way that shows a lack of skill or experience, often done by someone who is not a professional.
He played the guitar amateurishly at the open mic night.
Amateurishly → It is formed from "amateur" (from French *amateur*, meaning one who loves or is fond of) and the suffix "-ly" (meaning in a manner of). The word "amateurishly" describes doing something in a manner characteristic of an amateur, or lacking professional skill.
Think of someone who does something out of 'love' ('amateur') and not as a professional, and the '-ly' shows how they do it. This helps you remember that 'amateurishly' means doing something in a non-professional way.