What does adherent mean?
The definition of adherent
Ad*her”ent, a.
Etym: [L. adhaerens, -entis, p. pr.: cf. F. adhérent.]

1 Sticking; clinging; adhering. Pope.
2 Attached as an attribute or circumstance.
3 (Bot.)
Congenitally united with an organ of another kind, as calyx with ovary, or stamens with petals.

Ad*her”ent, n.
1 One who adheres; one who adheres; one who follows a leader, party, or profession; a follower, or partisan; a believer in a particular faith or church.
2 That which adheres; an appendage. [R.] Milton.

Synonyms
— Follower; partisan; upholder; disciple; supporter; dependent; ally; backer.