(1):

(a.) Not tilled, cultivated, or built upon; yielding no revenue; as, unimproved land or soil.

(2):

(a.) Not used; not employed; especially, not used or employed for a valuable purpose; as, unimproved opportunities; unimproved blessings.

(3):

(a.) Not improved; not made better or wiser; not advanced in knowledge, manners, or excellence.