IPA: /nɒnˈpɜːrfɔːrmər/
KK: /nɑnˈpɜrˌfɔr mər/
A person who does not perform well or fails to meet expectations, especially in a job or task.
In the meeting, the manager pointed out that the team had a few nonperformers who needed to improve their work.
Nonperformer → It is formed from "non-" (meaning not) and "performer" (from Latin "performare", meaning to carry out or accomplish). The word "nonperformer" refers to someone who does not carry out or accomplish tasks or duties.
Think of 'not' ('non-') doing something 'accomplished' ('performare') — that's why a nonperformer is someone who does not accomplish tasks.