dilator vs surgical instrument

dilator and surgical instrument both are nouns.

Word	Noun	Adjective	Verb	Adverb
dilator	Yes	No	No	No
surgical instrument	Yes	No	No	No

As nouns, surgical instrument is a hypernym of dilator; that is, surgical instrument is a word with a broader meaning than dilator:

dilator: a surgical instrument that is used to dilate or distend an opening or an organ
surgical instrument: a medical instrument used in surgery

dilator (noun)	surgical instrument (noun)
a surgical instrument that is used to dilate or distend an opening or an organ	a medical instrument used in surgery
a drug that causes dilation
a muscle or nerve that dilates or widens a body part