The word "gunkiest" is an adjective that describes something that is filled with gunk or sticky residue. There are several synonyms for this term that can be used interchangeably, including grimiest, filthiest, dirtiest, and foulest. These words describe something that is covered in an unclean, unpleasant substance or material. Other synonyms for "gunkiest" include muddiest, slimiest, and messiest. These words are often used to describe objects or materials that have become caked in dirt and grime, such as old machinery or dirty clothing. When describing something that is especially unclean or gross, any of these synonyms for "gunkiest" can effectively get the point across.