knob vs projection

knob and projection both are nouns.

Word	Noun	Adjective	Verb	Adverb
knob	Yes	No	No	No
projection	Yes	No	No	No

As nouns, projection is a hypernym of knob; that is, projection is a word with a broader meaning than knob:

knob (noun)	projection (noun)
a round handle	the act of expelling or projecting or ejecting
a circular rounded projection or protuberance	the act of projecting out from something
an ornament in the shape of a ball on the hilt of a sword or dagger	any structure that branches out from a central support
any thickened enlargement	the representation of a figure or solid on a plane as it would look from a particular direction
	a planned undertaking
	a prediction made by extrapolating from past observations
	the projection of an image from a film onto a screen
	the acoustic phenomenon that gives sound a penetrating quality
	(psychiatry) a defense mechanism by which your own traits and emotions are attributed to someone else
	any solid convex shape that juts out from something