Puzza vs. puzzo vs. fetore

The Italian language has several words to describe unpleasant odors, with 'puzza', 'puzzo', and 'fetore' being common choices. While they all relate to bad smells, they have subtle differences in usage and intensity.

Puzza

'Puzza' is a noun that refers to a general bad smell or stink. It's the most common and versatile of the three words.
C'è puzza di bruciato in cucina.
(There's a smell of burning in the kitchen.)
La puzza di spazzatura è insopportabile.
(The stench of garbage is unbearable.)

Puzzo

'Puzzo' is also a noun, but it typically implies a stronger, more offensive odor than 'puzza'. It's often used for particularly foul or disgusting smells.
Il puzzo dei piedi sudati riempiva la stanza.
(The stink of sweaty feet filled the room.)
Il puzzo di pesce marcio era nauseante.
(The stench of rotten fish was nauseating.)

Fetore

'Fetore' is a noun that describes an extremely strong, putrid, and often repulsive smell. It's the most intense of the three and is used for the worst odors.
Il fetore della discarica si sentiva a chilometri di distanza.
(The stench of the landfill could be smelled miles away.)
Il fetore della carcassa in decomposizione era insopportabile.
(The stench of the decomposing carcass was unbearable.)

Summary

While 'puzza', 'puzzo', and 'fetore' all describe bad smells, they differ in intensity. 'Puzza' is the most general term for an unpleasant odor, 'puzzo' implies a stronger, more offensive smell, and 'fetore' is reserved for the most putrid and repulsive stenches. Choose the appropriate word based on the severity of the odor you're describing.