Emily Dickinson Lexicon

FIF'TI-ETH, a. [Sax. fifteogetha; fif, five, and teogetha, tenth.]

The ordinal of fifty; as, the fiftieth part of a foot. This may be used elliptically; as, a fiftieth of his goods, part being understood; or in this case, the word may be treated in grammars as a noun, admitting a plural; as, two fiftieths.