Something that is malodorous has a very bad smell.
Malodorous things are usually not good because they smell very bad.
Examples:
The malodorous garbage made everyone cover their noses.
The malodorous socks were left under the bed.
She didn't want to go near the malodorous bathroom.
The malodorous cheese made the whole kitchen stink.
The malodorous skunk sprayed its stinky smell everywhere.
The malodorous flower smelled worse than the garbage.