Uneven

wiktionary

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From 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”).

etymonline

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uneven (adj.)

Old English unefen "unequal, unlike, anomalous, irregular," from un- (1) "not" + even (adj.). Similar formation in Old Frisian oniovn, Middle Dutch oneven, Old High German uneban, German uneben, Old Norse ujafn. Meaning "broken, rugged" (in reference to terrain, etc.) is recorded from late 13c. Related: Unevenly; unevenness.