Dilator

n.	1.	One who, or that which, widens or expands.
	2.	(Anat.) A muscle that dilates any part.
	3.	(Med.) An instrument for expanding a part; as, a urethral dilator.

Noun	1.	dilator - a muscle or nerve that dilates or widens a body part
	2.	dilator - a drug that causes dilation
	3.	dilator - a surgical instrument that is used to dilate or distend an opening or an organ Synonyms: dilater

body part, dilate, distend