Meaning

noun a small natural hill

originFrom Middle English knol, knolle, from Old English cnoll (“summit”), from Proto-Germanic *knudan-, *knudla-, *knulla- (“lump”), possibly related to cnotta. Related to Old Norse knollr (found only in names of places), Dutch knol (“tuber”), Swedish knöl (“tuber”), Danish knold (“hillock, clod, tuber”) and German Knolle (“bulb”).

Etymology from Wiktionary, CC BY-SA 3.0