cardinal compass point vs S

cardinal compass point and S both are nouns.

Word	Noun	Adjective	Verb	Adverb
cardinal compass point	Yes	No	No	No
S	Yes	No	No	No

As nouns, S is a hyponym of cardinal compass point; that is, S is a word with a more specific, narrower meaning than cardinal compass point:

Other hyponyms of cardinal compass point include due north, N, north, northward, due east, E, east, eastward, due south, south, southward, due west, W, west, westward.

cardinal compass point (noun)	S (noun)
one of the four main compass points	(thermodynamics) a thermodynamic quantity representing the amount of energy in a system that is no longer available for doing mechanical work
	the 19th letter of the Roman alphabet
	a unit of conductance equal to the reciprocal of an ohm
	the cardinal compass point that is at 180 degrees
	an abundant tasteless odorless multivalent nonmetallic element; best known in yellow crystals; occurs in many sulphide and sulphate minerals and even in native form (especially in volcanic regions)