Meaning

adjective not even or uniform as e.g. in shape or texture

adjective (of a contest or contestants) not fairly matched as opponents

adjective not divisible by two

originFrom Middle English uneven, from Old English unefen (“unequal, unlike, dissimilar, diverse, irregular”), equivalent to un- + even. Cognate with Dutch oneven (“unequal, uneven, odd”), German uneben (“uneven, rough, irregular, bumpy”).

Etymology from Wiktionary, CC BY-SA 3.0