-ist

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

rhizotomist
rigorist
1. Someone who is of strict or rigid principles or manners.

In general, a person who adheres to severity or purity in anything.

2. Characterized by strictness or severity in principles or practice; rigid; strict; exacting.
ritualist
robotophilist
A collector of remote control gear.
roentgenologist
Radiologist, a physician who uses x-rays or other sources of radiation for diagnosis and treatment.
rotuliphilist
A collector of baby rattles.
routinist (s) (noun)
royalist
ruralist (s) (noun), rualists
1. Someone who resides or lives in a country area instead of towns or cities.
2. A person who advocates or considers living in the country is better than being in cities where so many people are living.
saccrophilist
A collector of wrapped lumps of sugar.
sacerdotalist (s) (noun), sacerdotalists (pl)
Anyone who has a religious belief that priests are essential mediators between God and humankind: Melanie's elderly aunt was a sacerdotalist and often asked her priest to visit her for prayer and comfort.
sacramentalist (s) (noun), sacramentalists (pl)
Someone who believes in or uses symbolic rites, acts, or objects; specifically, with the belief that such practices are inherently efficacious and necessary for one's salvation: Despite her confidence in her pastor, Dora felt that sometimes his emphasis on sacramentalists was too excessive for her comfort.
salvationist (s) (noun), salvationists (pl)
1. A member of the Salvation Army.
2. Someone who preaches salvation, deliverance from sin, etc., and the means of obtaining it; an evangelist or preacher.
sambotahphilist
A collector of military uniforms.
santicolist
Someone who worships saints.