projection vs spine

projection and spine both are nouns.

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

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

projection (noun)	spine (noun)
the act of expelling or projecting or ejecting	a sharp rigid animal process or appendage; as a porcupine quill or a ridge on a bone or a ray of a fish fin
the act of projecting out from something	the part of a book's cover that encloses the inner side of the book's pages and that faces outward when the book is shelved
any structure that branches out from a central support	the series of vertebrae forming the axis of the skeleton and protecting the spinal cord
the representation of a figure or solid on a plane as it would look from a particular direction	a small sharp-pointed tip resembling a spike on a stem or leaf
a planned undertaking	any sharply pointed projection
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