calibre vs diameter

calibre and diameter both are nouns.

Word	Noun	Adjective	Verb	Adverb
calibre	Yes	No	No	No
diameter	Yes	No	No	No

As nouns, diameter is a hypernym of calibre; that is, diameter is a word with a broader meaning than calibre:

calibre: diameter of a tube or gun barrel
diameter: the length of a straight line passing through the center of a circle and connecting two points on the circumference

Other hypernyms of calibre include diam.

calibre (noun)	diameter (noun)
a degree or grade of excellence or worth	the length of a straight line passing through the center of a circle and connecting two points on the circumference
diameter of a tube or gun barrel	a straight line connecting the center of a circle with two points on its perimeter (or the center of a sphere with two points on its surface)