knopper

noun

knop·​per

ˈnäpə(r)

plural -s

: a gall that is formed by a gall wasp on the leaves and immature acorns of various oaks and that is used in tanning and dyeing

Word History

Etymology

German; akin to Old High German knopf knot, bud, knob

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!