public vs admass

public and admass both are nouns.

Word	Noun	Adjective	Verb	Adverb
public	Yes	Yes	No	No
admass	Yes	No	No	No

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

public: people in general considered as a whole
admass: the segment of the public that is easily influenced by mass media (chiefly British)

public (noun)	admass (noun)
people in general considered as a whole	the segment of the public that is easily influenced by mass media (chiefly British)
a body of people sharing some common interest

public (adjective)	admass (adjective)
not private; open to or concerning the people as a whole
affecting the people or community as a whole