Emily Dickinson Lexicon

SES-QUIP'E-DAL, or SES-QUIP-E-DA'LI-AN, a. [L. sesqui, one and a half, and pedalis, from pes, a foot.]

Containing a foot and a half; as, a sesquipedalian pigmy. Arbuthnot. Addison uses sesquipedal as a noun.