Intellectually or spiritually unenlightened; lacking knowledge, ignorant; uninformed. Now rare.

Not illuminated by reason, faith, logic, truth, etc.

Theology. Of a person: spiritually unenlightened; unregenerate; having a belief system or world view uninformed by revelation. Obsolete.

Made dark; enveloped in darkness. Chiefly figurative: lacking knowledge, understanding, or insight; marked by a lack of enlightenment.

figurative. Involved in intellectual or moral darkness.

(un-, prefix1 affix 2.)

Not illuminated by rays of light; figurative not lightened by some positive or beneficial influence.

Made dark (in various senses).