(Greek > Latin: a suffix; one who believes in; one who is engaged in; someone who does something)

abiogenist (s) (noun), abiogenists (pl)
A person who holds or advocates the hypothesis of the organic phenomenon by which living organisms are created from nonliving matter: There was a whole school of abiogenists during the 17th century who are now the subject of amusement in modern science.
abolitionist (ab" uh LISH uh nist) (s) (noun), abolitionists (pl)
1. Someone who supports getting rid of something, such as a system, a practice, or an institution: Stanley was considered an abolitionist who led the students' cause to eliminate unfair grading systems.

Abolitionists believed that slavery violated the basic human rights of freedom and so they insisted on making slavery illegal by proposing new antislavery laws for the country.

The most influential publication before the Civil War was Uncle Tom’s Cabin (1852), the best-selling novel and play by Harriet Beecher Stowe, the most famous abolitionist of the time.

Harriet Stowe emphasized the horrors that abolitionists had long claimed about slavery.

2. People who want to destroy a law or practice of some kind: The abolitionists against the cruel treatment of animals included several groups across the entire country.

As an abolitionist, Monroe Jones fought to end the practice of slavery in the United States before the Civil War.

The elimination of slavery and the conflict between the abolitionists and those in favor of slavery were factors that led to the Civil War in America.

abortionist (s) (noun), abortionists (pl)
1. Someone who believes and promotes the ending of a pregnancy: The speaker was a well-known abortionist who advocated supporting the legal termination of pregnancies.
2. An individual who makes a business of ending a pregnancy illegally: The backstreet abortionist has recently been arrested by the police.
3. People who support, or advocate ending pregnancies when a woman wants it to be done: The noisy crowd in front of the clinic included many well-known abortionists.
4. Anyone who takes the action of stopping a project, a mission, etc, before it is completed: The engineer for the city was an abortionist who advocated discontinuing the building of the expensive bridge because of the excessive costs.
abrakophile, abrakophilist (s) (noun); abrakophiles; abrakophilists (pl)
Someone who has a desire for finding and keeping knickknacks or trinkets: Mr. Sampson, who was the local abrakophile, often attended antique shows looking for interesting items to add to his collections.
absurdist (s) (noun), absurdists (pl)
1. Someone who considers something as being extremely silly, unreasonable, or foolish: Ted's lawyer claimed that the charges made by the absurdist in the police department were obviously unfounded because Ted was in another country when the crime was committed.
2. A person who acts or presents characteristics of being ridiculous: Mr. Potter, the politician, was described by some people as another in a series of absurdists who were candidates for mayor.
acanthologist (s) (nouns), acanthologists (pl)
A person who studies spiny creatures: Jim's father was an acanthologist who was a specialist in sea urchins and worms with spiny-heads and classified them into taxonomic groups.
acarologist (s) (noun), acarologists (pl)
A specialist in acarology or the scientific study of mites and ticks: Dick's father was an acarologist and worked together with other experts in a lab doing research on arachnids.
acosmist (s) (noun), acosmists (pl)
Someone who denies the existence of the universe or of a universe that is distinct from God.
Anyone, or anything, which does not consume meat.
acuologist (s) (noun), acuologists (pl)
A specialist in the use of needles for therapeutic reasons: Dr. Black, an acuologist, suggested a treatment with special acupuncture needles to relieve Sally's back pains.
acupressurist (s) (noun), acupressurists (pl)
Someone who applies force to a body area for therapeutic purposes: Dr. Nelson was an acupressurist who was renown for his alternative medical treatment by using physical force on certain body parts of patients to relieve their pains.
acupunturist (s) (noun), acupuncturists (pl)
One who practices acupuncture: Dr. Johnson was a professional healthcare specialist in the field of acupuncture and had the title of being an acupuncturist, and believed strongly in curing patients of their ailments by the use of needles or thin pins.
addictionologist (s) (noun), addictionologists (pl)
A specialist in the study and treatment of those who are physiologically or mentally dependent on tobacco, alcohol, or other substances: His father was such a slave to smoking and booze, that it motivated Bryon to study and to become an addictionologist so he could help his father, and others, to overcome their uncontrollable dependence on such dangerous elements.
1. Anyone who participates in the practice of adelphogamy.
2. An advocate or supporter of adelphogamy.