IPA: /ˌmæl.əˈdɔːr.əs.nəs/
KK: /mælˈoʊdərəsnəs/
The condition of having a bad smell.
The malodorousness of the garbage made it hard to stay nearby.
Malodorousness → It is formed from "mal-" (meaning bad) and "odor" (from Latin "odor", meaning smell) and the suffix "-ous" (meaning full of) and "-ness" (meaning the state of). The word describes the state of being full of a bad smell.
Think of 'mal-' meaning bad and 'odor' meaning smell — this helps you remember that 'malodorousness' refers to the state of having a bad smell.