n. An odor that a person continues to smell even in the absence of the original odorant.
Walking away after a morning episode comparing almond, walnut, peach, apricot, cherry, and prune, I find that the whole room smells like prune. I step outside with Finnegan; a wind wrests the screen door from my grip. His nose rises to attention at the passing air. I smell … prune. I have been afflicted with a prune noseworm.
—Alexandra Horowitz, Being a Dog, Simon and Schuster, October 04, 2016
A true noseworm, if it exists, would be something different. It’s possible that when you get a whiff of something weird, such as castoreum (a secretion from beaver butts), a snapshot of the odor sticks with you. That might be because the fragrance has clung to your shirt or your nose hairs, Gilbert says, or it could be a kind of “mental resonation” that “sticks in your nose, and you keep smelling it throughout the day.”
—Daniel Engber, “Can You Get a Smell Stuck In Your Head?,” Popular Science, July 08, 2015
I don't get earworms so much as noseworms. Smells that haunt me. Fresh baked bread. Watermelon. Bar-b-que flavor potato chips. It usually haunts me until I'm driven into the kitchen to forage. This is a major disadvantage of working at home.
—Hallie Ephron, “On Earworms,” Jungle Red, August 13, 2007
1999 (earliest)
> Eeeeewwwww…. What's the olfactory equivalent of an earworm??

A noseworm perhaps?
—Richard Jasper, “Cologne Queen,” soc.motss, March 12, 1999