The word "washable" is a modern English compound formed by combining the native Germanic verb "wash" with the Latinate adjectival suffix "-able". The root "wash" originates from the Proto-Germanic watskan, which carries the fundamental sense of cleaning with water. The suffix "-able" entered English via Old French from the Latin -abilis, a productive suffix used to form adjectives expressing capacity or susceptibility. The fusion of these elements creates a transparent and logical meaning: an object possessing the inherent quality or capacity to undergo the action of washing. This pattern of attaching "-able" to verb roots is a highly productive method in English for creating adjectives that describe functional properties.

Structure: wash (to clean with water) + able (capable of) - wash: From Old English wæscan, meaning "to wash, cleanse, bathe". Its functional role is the core verb root. - able: From Latin -abilis, a suffix forming adjectives meaning "capable of, fit for, tending to". Its functional role is a derivational suffix.