IPA: //ʌˈniːvən//
KK: /ʌˈnivən/
Not level or smooth; having an irregular surface or shape.
The road was uneven, making it difficult to ride my bike.
Comparative: more uneven
Superlative: most uneven
Unevener → It is formed from "un-" (meaning not) and "even" (from Old English "efen", meaning level or equal) and the suffix "-er" (meaning one who). The word "unevener" describes someone or something that is not level or equal.
Think of 'not' ('un-') being added to 'level' ('even') — this helps you remember that 'unevener' refers to something that is not level.