The story
A shortening of pockerchicory/pokickery/pohickery, from Powhatan pawcohiccora.
Etymology from Wiktionary, CC BY-SA 4.0.
hickory
Today it means: Any of various deciduous hardwood trees of the genera Carya and Annamocarya, one species of which, Carya illinoinensis, is the source of pecan nuts. Full definition →