Noisome looks and sounds like a close relation of noisy, but it’s not. While noisy describes what is excessively loud, noisome typically describes what is excessively stinky. (It is also used to describe things offensive to the senses generally, as well as things that are highly obnoxious, objectionable, or simply harmful.) Noisome comes from the synonymous Middle English noysome, which combined the suffix -some, meaning “characterized by a specified thing,” and the noun noy, meaning “annoyance.” Noisy, incidentally, comes ultimately from Latin nausea, meaning “nausea.”