Wiktionary
oak apples
n. (oak apple English)
Usage examples of "oak apples".
A male oak tree - he'd have to look this up - a male oak tree just shed its pollen on the breeze and all the business with the acorns, unless it was oak apples, no, he was pretty sure it was acorns, took place somewhere else .
Instead, Frith sent them strange singers, beautiful and sick like oak apples, like robins' pincushions on the wild rose.