Definition of "dilator" [di•lat•or]

• A muscle that dilates a body part, such as a blood vessel or the pupil of the eye. (noun)
• An instrument that dilates a body part, such as a cavity, canal, or orifice. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The woman returns a second day so doctors either can insert more laminaria or another dilator, or remove the fetus and complete the abortion."
• "On the first day, doctors insert a dilator, often bundles of dried seaweed called laminaria, to soften a woman's cervix."
• "If a woman changes her mind after the dilator has been inserted and seeks to reverse the process, doctors can remove the laminaria."