noun
- abnormal growths on oak trees and other plants caused by insects, used historically to make ink and dyes
Usage: plural form; historical
Examples
- Medieval scribes made ink from nutgalls and iron sulfate.
- The wasp larvae develop inside the nutgalls on oak branches.
- Nutgalls were once an important trade commodity for making black dye.
- The tannins in nutgalls made them valuable for leather processing.
- Collectors gathered nutgalls from oak trees each autumn.
- Traditional ink recipes called for crushing dried nutgalls.