Emily Dickinson Lexicon

STALL-ION, n. [stal'yun; G. hengst; Dan. staldhingst; Fr. etalon; It. stallone; from stall, or its root, as we now use stud horse, from the root of stud, stead; W. ystal, a stall, stock, produce; ystalu, to form a stock; ystalwyn, a stallion.]

A stone horse; a seed horse; or any male horse not castrated, whether kept for mares or not. According to the Welsh, the word signifies a stock horse, a horse intended for raising stock.