"Merdurinous" is a relatively rare word that is often used to describe something that is dirty or unclean. However, there are a number of synonyms that can be used in its place, depending on the context and the intended tone. Some possible synonyms include "filthy," "foul," "disgusting," "mucky," "unclean," "grimey," "nasty," "putrid," "repulsive," "revolting," "squalid," and "vile." Each of these words conveys a slightly different nuance, so it's important to choose the right synonym to best express the intended meaning. Regardless of the synonym used, however, it's clear that merdurinous things are not pleasant or desirable.