Valonia \Va*lo"ni*a\, n. [It. vallonia, vallonea, fr. NGr. balania`, balanidia`, the holm oak, bala`ni, balani`di, an acorn, Gr. ba`lanos.] 1. The acorn cup of two kinds of oak ({Quercus macrolepis}, and {Q. vallonea}) found in Eastern Europe. It contains abundance of tannin, and is much used by tanners and dyers.