n 1  :  the passive rhythmical expansion or dilation of the cavities of the heart during which they fill with blood - compare SYSTOLE   2  :  the rhythmical expansion of a pulsating vacuole (as of an ameba) di*a*stol*ic adj 
 
 
 
Similar sounding terms:   diacetyl  dis·tal  dis·till 
 
Published under license with Merriam-Webster, Incorporated.  © 1997-2024.