oak appleEnglishOxford Dictionary of Englishoak apple ▸ noun a spongy spherical gall which forms on oak trees in response to the developing larvae of a gall wasp. The wasp is Biorhiza pallida (in Europe) or Amphibolips confluenta (in America), family Cynipidae.
EnglishOxford Dictionary of EnglishEnglishOxford Dictionary of English
EnglishOxford Dictionary of English