Dilator (noun)

1. A medical instrument used to widen or dilate a passage or opening in the body.
2. A device used to expand a passage or opening.

Origin:

From the latin word "dilatare" meaning "to expand, to widen, to enlarge".

Examples:

1. The gynecologist used a dilator to widen the cervix.
2. The surgeon used a dilator to open the narrowed artery.
3. The dilator was used to open the blocked nasal passage.
4. The dilator was used to widen the opening of the urethra.
5. The dilator was used to open the narrowed esophagus.