any of various rounded galls produced on oaks, especially the horned oak gall.
Origin of oak gall
First recorded in 1760–70
Also called oak apple.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for oak gall
Historical Examples of oak gall
Waterproof inks are sometimes used, and of these the oak-gall ink is undoubtedly the best.