dīˈlāshən, də̇ˈ-, ÷ˌdīəˈl- noun
( -s )
Etymology: dilate (I) + -ion
1. : the act of dilating or the state of being dilated : expansion , dilatation
2. : the action of stretching or enlarging an organ or part of the body
dilation of the cervix
dilation of the pupil by atropine