unlike
adj.
c.1200, "not resembling," from un-(1) "not" + like, adj.. Similar formation in Old English ungelic, Old Frisian unlik, Old Norse ulikr, Middle Danish ulige, German ungleich.
adv.
c.1300, "unevenly," from un-(1) "not" + like (adv.) (see like, adj.). From 1590s as "in a manner differing."