Pronunciation: (dil"u-tā'shun, dī"lu-),[key] —n. 1. a dilated formation or part.
2. Pathol.an abnormal enlargement of an aperture or a canal of the body.
3. Surg. a. an enlargement made in a body aperture or canal for surgical or medical treatment.
b. a restoration to normal patency of an abnormally small body opening or passageway, as of the anus or esophagus.
4. Mech.the increase in volume per unit volume of a homogeneous substance. Also,dilation.