IPA: /ˈlʌm.pi.ər/
KK: /ˈlʌmpɪər/
Having a rough or uneven surface with bumps or lumps; more uneven than something that is lumpy.
The old mattress was lumpier than the new one, making it uncomfortable to sleep on.
Comparative: lumpier
Superlative: lumpiest
Lumpier → It is formed from "lump" (from Middle English "lumpe", meaning a mass or clump) and the suffix "-ier" (meaning more). The word "lumpier" describes something that has more lumps or is characterized by lumps.
Think of a 'lump' as a mass or clump, and remember that 'lumpier' means having more of those masses.