ratty

The word 'ratty' is a straightforward English formation, combining the noun 'rat' with the adjectival suffix '-y'. The rodent 'rat' has long been associated with negative qualities such as dirtiness, infestation, and low social standing. By the mid-19th century, applying the suffix '-y' (meaning "having the character of") created the adjective 'ratty' to describe things that are shabby, worn-out, or infested, evoking the unpleasant conditions associated with rats. Later, this metaphorical extension was applied to human temperament, suggesting irritability thought to resemble the perceived aggressive or unpleasant nature of the animal.

Structure: rat (rodent) + y (adjective suffix) - rat: From Middle English rat, from Old English ræt, of uncertain ultimate origin, possibly from Proto-Germanic. Functions as the base noun denoting the rodent. - y: A productive English suffix forming adjectives, from Old English -ig, from Proto-Germanic -igaz. It means "characterized by; full of; having the qualities of".