rat-infested

The compound 'rat-infested' is a straightforward descriptive term from Modern English. The first element, 'rat', is an ancient Germanic word for the rodent, likely onomatopoeic in origin. The second element, 'infested', derives from the Latin infestus, meaning hostile or dangerous, which evolved to describe a place being overrun or plagued by something troublesome. The logic of the compound is transparent: it literally describes a place that is hostilely occupied or plagued by rats, conveying a strong sense of squalor and neglect.

Structure: rat (rodent) + infested (overrun) - rat: From Old English ræt, of unknown origin. Functions as a noun root specifying the type of pest. - infested: From Latin infestus (hostile, aggressive), via the verb infestare (to attack, disturb). The past participle form -infested functions as a combining adjective meaning "overrun by (something harmful)."