D defs.my
Entry 1 sense Webster, 1913

Knoppern

· Knop·pern · IPA
01 n. A kind of gall produced by a gallfly on the cup of an acorn, -- used in tanning and dyeing.
  1. 1.
    A kind of gall produced by a gallfly on the cup of an acorn, -- used in tanning and dyeing.(Zool.)