adherent

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A supporter, as of a cause or individual.
• adjective Sticking or holding fast.
• adjective Botany Joined but not united. Used of dissimilar parts or organs.

from The Century Dictionary.

• Sticking; clinging; adhering.
• In botany, congenitally united, as parts that are normally separate: generally used as equivalent to adnate. See cut under adnate. In logic and metaphysics, accidentally connected; not belonging to the nature of a thing; not inherent: as, if a cloth is wet, its wetness is a quality adherent to it, not inherent in it.
• noun A person who adheres; one who follows or upholds a leader, party, cause, opinion, or the like; a follower, partizan, or supporter.
• noun Anything outwardly belonging to a person; an appendage.
• noun Synonyms Disciple, pupil, upholder, supporter, dependant.

from the GNU version of the Collaborative International Dictionary of English.

• noun 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.
• noun rare That which adheres; an appendage.
• adjective Sticking; clinging; adhering.
• adjective Attached as an attribute or circumstance.
• adjective (Bot.) Congenitally united with an organ of another kind, as calyx with ovary, or stamens with petals.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Adhesive, sticking to something.
• adjective Having the quality of clinging or sticking fast to something.
• adjective botany Attaching or pressing against a different organ.
• noun A person who has membership in some group, association or religion.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective sticking fast
• noun someone who believes and helps to spread the doctrine of another