Emily Dickinson Lexicon

DI-AS'TO-LE, or DI-AS'TO-LY, n. [Gr. διαςολη, διαςελλω; δια and ςελλω, to set, or send from.]

1. Among physicians, a dilatation of the heart, auricles and arteries; opposed to systole or contraction. – Encyc.
2. In grammar, the extension of a syllable; or a figure by which a syllable naturally short is made long.