The Collaborative International Dictionary
Yoncopin
Yoncopin \Yon"co*pin\, n. [Perhaps corrupted from Illinois micoupena, Chippewa makopin, the American lotus.] (Bot.) A local name in parts of the Mississippi Valley for the American lotus ( Nelumbo lutea).
Wiktionary
yoncopin
n. (context US Mississippi dialect English) ''Nelumbo lutea'', the American lotus, the (vern water chinkapin pedia=1).