dilation /dīlā″shən/ [L, dilatare, to widen] , 1. the condition of being dilated or stretched. 2. the process of causing a physiological increase in the diameter of a body opening, blood vessel, or tube. Examples include the widening of the pupil of the eye by the use of cycloplegic eyedrops for examination of the retina and opening of the uterine cervix to facilitate curettage by the use of a dilator. Also called dilatation.
