nub (n.)

late 14c., knobe, probably from a Scandinavian or German source (compare Middle Low German knobbe "knob," Middle Dutch cnoppe, Dutch knop, Old Frisian knopp, knapp, Old High German knopf, German Knopf "button," Old Norse knyfill "short horn"). Meaning "knoll, isolated round hill" is first recorded 1640s, especially in U.S. For pronunciation, see kn-.

"stunted ear of corn," 1690s, American English colloquial diminutive of nub. General sense of "small piece" is from 1857.

"full of entanglements or imperfections," 1864, from nub + -y (2). Nubbly, "having numerous knobs or lumps," is from 1814.