-ist

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

xylophonist
One who plays a xylophone.
xylopolist
1. One who sells timber; a timber-merchant.
2. A dealer in wooden objects or one who sells various kinds of wood or wooden objects.
xylotomist
That which cuts or pierces wood; such as, an insect.
yappophilist
A collector of limp-leather books.
zelotypist (s), zelotypists (pl) (noun forms)
Someone who is characterized, or marked, by excessive zeal that is carried to the verge of insanity, in the advocacy of some cause.
zoiatrist
Someone who specializes in the medical treatment of animals; more commonly known as a veterinarian.
zoologist (s) (noun), zoologists (pl)
A scientist specializing in the discipline of zoology; an expert in zoology: Mary's uncle wanted to become a zoologist so he had to study zoology in order to focus on this field of science and do research in this area.
zoomantist (s) (noun), zoomantists (pl)
A person who thinks animal behavior is a means of predicting future events: Mary's uncle, a zoomantist, believed that a storm was approaching when Toby, his cat, hid under the bed and wouldn't come out to eat.
zoometrist (s) (noun), zoometrists (pl)
A specialist who uses statistical methods in the study of animals: Mr. Anderson was a zoometrist, or an expert, in the field of applied mathematics involving the collection and interpretation of data in the survey of faunae.
zoonomist (s) (noun). zoonomists (pl)
A specialist in the laws of animal life: Tommy wanted to become a zoonomist who deals with the facts and marvels of the lives of faunae.
zoonosologist (s) (noun), zoonosologists (pl)
A specialist in the diseases of animals: Jim's father was a zoonosologist who classified the disorders and illnesses of animals.
zoopraxographist (s) (noun), zoopraxographists (pl)
Someone who is a specialist in the subject of the way animals make progress from one position to another one: A zoopraxographist studies and records the various ways certain animals walk and run.
zootheist (s) (noun), zootheists (pl)
A person who believes a god is in the form of an animal: A zoothiest is an individual who worships animal deities.
zootomist (s) (noun), zootomists (pl)
A person who is involved with the anatomy of animals: Dr. Smith, a zootomist, was in the lab and dissecting the body of a pig and preparing it for his lecture in zootomy.
zymologist (s) (noun), zymologists (pl)
Someone who specializes in the branch of chemistry concerned with fermentation: A zymologist is skilled in making wine, brewing, or distilling alcoholic beverages and so it is necessary that he or she has a knowledge of the techniques in the breaking down of organic substances into simpler ones.