projection vs knob

projection and knob both are nouns.

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

As nouns, knob is a hyponym of projection; that is, knob is a word with a more specific, narrower meaning than projection:

projection (noun)	knob (noun)
the act of expelling or projecting or ejecting	a round handle
the act of projecting out from something	a circular rounded projection or protuberance
any structure that branches out from a central support	an ornament in the shape of a ball on the hilt of a sword or dagger
the representation of a figure or solid on a plane as it would look from a particular direction	any thickened enlargement
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