Noisome

noisome [NOY-sum]
adj. disgusting or offensive, as odor; noxious

[Derives from annoy, which came from Old French anuier ("to molest; harm")]

The noi- in noisome is an aphonic variation of annoy -- that is, the first syllable was originally mouthed but not pronounced. In time, the first syllable was dropped altogether. Understanding that, it's easy to see how a disgusting odor can be annoying and hence noisome.

We have a number of good synonyms in English to describe bad smells, but only stinky and smelly are commonly used. A few other adjectives I can think of are: acrid ("unpleasantly sharp, pungent, or bitter to the taste or smell"), effluvial ("having odorous fumes given off by waste or decaying matter"), fetid ("having an offensive odor"), foul ("grossly offensive to the senses"), frowzy ("ill-smelling"), funky ("having an offensive smell"), fusty ("having a stale smell"), gamy ("having the odor of game, especially game that is slightly spoiled"), malodorous ("having an unpleasant or offensive odor"), mephitic ("offensive to the smell"), noxious ("harmful or injurious to health"), putrid ("in a state of foul decay"), rancid ("having a rank, unpleasant, stale smell or taste"), rank ("having an offensively strong smell"), reeky ("having a strong, unpleasant smell") and rotten ("tainted, foul, or bad-smelling").

In Theodore Rex, Edmund Morris described a populist (and racist) senator from South Carolina, Benjamin Tillman, as being like the mythical Paul Bunyan, unfamiliar with taking a bath:

Bunyan's noisome figure, more interested in piling up dirt than stargazing, duly made every major newspaper in the country.