‖Di‐as″to‐le (?), n. [L., fr. Gr. �, fr. � to put asunder, to separate; διά through + � to set, to place.] 1. (Physiol.) The rhythmical expansion or dilatation of the heart and arteries; — correlative to systole, or contraction.
2. (Gram.) A figure by which a syllable naturally short is made long.