IPA: //ˈnɔɪsəm//
KK: /ˈnɔɪsəm/
Something that is harmful or offensive, especially in a way that causes disgust or discomfort.
The noisome smell from the garbage made it hard to breathe.
Noisome is derived from the Middle English 'noisome' (meaning harmful or offensive), which comes from the Old English 'noysum' (meaning annoying or harmful) and is related to the word 'noise' (from Old French 'noise', meaning sound or disturbance). The word originally described something that causes annoyance or harm, particularly in terms of smell.
Think of something that is 'harmful' or 'offensive' — that's what noisome means, as it relates to causing annoyance or discomfort.