The word 'untilled' is a straightforward English formation built upon the ancient verb 'to till.' The root 'till' originates from Old English tilian, which meant "to labor, strive for, or cultivate," a sense closely tied to agriculture. The addition of the Old English negative prefix 'un-' creates the meaning "not cultivated." Finally, the past participle suffix '-ed' transforms the verbal idea into an adjectival state, describing land that remains in its natural, unworked condition. Thus, the word's logic is transparent: it literally describes land upon which the action of tilling has not been performed.

Structure: un (not) + till (to plow) + ed (adjective suffix) - un: A prefix of Germanic origin (Old English) meaning "not," used to form negatives. - till: A verb of Germanic origin (Old English tilian meaning "to strive for, cultivate") representing the core action of preparing soil. - ed: A suffix of Germanic origin (Old English) used to form adjectives from verbs, indicating a state or condition.