dilator

nouns

a muscle or nerve that dilates or widens a body part
is derived from
is a type of (narrower)
any part of an organism such as an organ or extremity
a drug that causes dilation
is derived from
is a type of (narrower)
a substance that is used as a medicine or narcotic
a surgical instrument that is used to dilate or distend an opening or an organ
is derived from