-or; -our (primarily British)

(Latin: a suffix; state of, result of; he who, that which)

A suffix that forms nouns. British spelling is usually -our.
pulsator (s) (noun), pulsators (pl)
rector (s) (noun), rectors (pl)
1. A priest in an Anglican church: The rector of the parish conducts religious services and also consults or gives advice to the individual members of his congregation.
2. A Roman Catholic priest appointed to be a manager as well as a spiritual head of a church or other institution, such as a seminary or university: The rector, or religious official, conducts certain rituals and sacraments in his place of worship.
3. A person who is in charge as the primary administrator of a certain educational institution, college, or university: The chief manager of some European schools are known as rectors.
re-enumerate (verb), re-enumerates; re-enumerated; re-enumerating
Determining or ascertaining the aggregates or rations of something again: Warren was asked to re-enumerate the items that he had purchased to be sure nothing was missing.

Fay was re-enumerating the reasons for not going on the trip with her friends.

refractor (s) (noun), refractors (pl)
An instrument which alters the direction of a beam of light by passing it between two transparent materials of different densities.
refrigerator
A cabinet or room for storing substances, as food, at a low temperature.
regulator (s) (noun), regulators (pl)
1. A gadget that controls something: The regulator on the radiator didn't work properly, and, although Nancy tried turning it down, it got hotter and hotter!.
2. An individual or an organizuation that establishes guidelines or criteria: The regulator officially controls a section of business and ensures that it is functioning well or is managed fairly.
3. A very precise clodk: In town there was a clockmaker who used a regulator in order to measure the timekeeping of the newly created clocks.
rejector
retractor
revelator
rotator
ruminator (s) (noun), ruminators (pl)
1. A reflective thinker characterized by quiet thoughtfulness: The head of the project urged his group to be ruminators and to come up with suggestions that would make the results of their efforts be of real value.
2. Someone who turns a subject over and over in his or her mind by thinking about it for a long time: As a serious ruminator, Jan spent some months trying to reach a decision as to whether she could really afford to spend so much money to go on a trip to Europe.
salivator
1. Any agent that causes salivation.
2. Someone who uses sialagogues.
3. To be envious, desirous, eager for, or extremely happy about something.
scintillator
1. A substance that emits visible light when hit by a subatomic particle or x-or gamma ray.
2. A phosphor capable of producing scintillations.
scotophor
Material, usually potassium chloride, that darkens under electron bombardment and is used for screens of cathode-ray tubes.
scrutator (s) (noun), scrutators (pl)
A person who is a conscientious examiner or inquirer: Mr. Dawson, the investment scrutator, had a reputation for successfully determining the best place to place people's money.