Other forms: noisomely
If you accidentally leave half a sandwich under your bed for a few days, cover your nose while you sleep because it will probably become quite noisome. This is a fancy way of saying that it will stink.
Despite that first syllable, this adjective doesn’t have root origins in the word noise; instead, it is related to the word annoy. Noisome can refer to anything unpleasant or anything that makes you feel a bit nauseous. However, it is most often used to describe things that smell badly. So spray some air freshener, open the windows, and clean out under your bed!