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Webster 1913 Edition

Noun.

(Zool.)

A round gall produced on the leaves and shoots of various species of the oak tree. See

, and

gallnut ‎(plural gallnuts)

A gall on a tree, caused by insects, that resembles a nut.
- 1916, James Joyce, Portrait of the Artist as a Young Man (Macmillan Press Ltd, paperback, page 62)
  There was the smell of evening in the air, the smell of the fields in the country where they digged up turnips to peel them and eat them when they went out for a walk to Major Barton's, the smell there was in the little wood beyond the pavilion where the gallnuts were.