What Greek words end in us?

Many Greek words ending in "-us" exist, and the ending itself can have different grammatical functions. To give you a proper answer, we need to know what kind of words you're interested in. "-us" can be:

* Part of the nominative singular of masculine nouns: Many nouns ending in -us in Latin have Greek origins. Examples include: virus, radius, focus. (Note that these are often adapted Latin forms, but their roots are Greek). There are many more purely Greek examples if you consider the original forms.

* Part of other grammatical cases (genitive, dative, etc.): The ending "-us" might be part of other grammatical forms. You'd need to specify the grammatical function you're looking for.

* Part of adjectives: Some Greek adjectives have masculine forms ending in "-us".

To get a more precise answer, please clarify what kind of Greek words you're interested in (nouns, verbs, adjectives, etc.) and possibly their grammatical function.