-or; -our (primarily British)

1. Someone who gives up a high office, formally or officially, especially a royal throne: The duke, by renouncing his title, was seen by many as an abdicator.
2. Anyone who fails to fulfill a duty or responsibility: The manager of the store lost his position because he was accused of being an abdicator of his duties.

1. Someone who illegally leads, or takes, another person away by force or deception: The description of the abductor matched the profile in the police station.
2. A muscle that pulls the body or a limb away from a midpoint or midline, such as raising the arm out from the side: Eric strained both abductors in his right arm when he tried to throw the baseball.

1. The heat shields of space vehicles, which melt or wear away during the reentry into the earth's atmosphere: The scientist created a new ablator which could withstand extreme heat.
2. The outer surface of a spacecraft or missile: "Ablation" is the erosion of the protective outer surface, or ablator, of a spacecraft or missile resulting from aerodynamic heating caused by travel at hypersonic speeds during reentry through the atmosphere.

The ablators on the spacecraft were welded into place using a specialized metal that would withstand great heat.

The mature embryo of an intestinal worm: The acanthor, which has beaklike hooks and spines on its body, digs into the body cavity of its first transitional or intermediate host, which is normally an aquatic crustacean or an insect.

1. A pedal or other device to make something go faster, to speed up, or to quicken the pace: The car suddenly lunged into a tree when Jeremy stepped too hard on the accelerator.
2. A machine used to increase the velocity, and hence the kinetic energy, of subatomic particles or nuclei; usually, in preparation for collision with a target.

A muscle that draws any limb, or part of the body, towards the trunk or main axis, or which folds or closes extended parts of the organism: When Meg was trying to open the oyster, she had to cut the adductor on the underside of the top shell.

A helper or assistant.

1. A device used to mix or combine air with a substance or medium: An aerator is used to expose soil or even sewage to air.

An aerator is used to charge mineral water with gas to produce soda water.
2. Specifically, a device installed in a faucet or shower head to add air to the water flow: An aerator serves the purpose of maintaining an effective spray while reducing overall water consumption.

A device that produces electricity by the power of wind: The aerogenerator was made especially for utilizing wind on a commercial basis.

A windmill is an example of an aerogenerator by converting mechanical energy into electrical energy.

1. A person or nation, that attacks or starts a war, a fight, or an argument, often without being provoked.
2. Anyone who initiates hostilities; such as, an assailant who attacks another person or who engages in some form of aggressive behavior.
3. Someone whose behavior may be violent, unpredictable, reactionary, and impulsive; for example, anyone who breaks the law.

1. A person who tries to stir up people in support of a social or political cause: often used in an unfavorable sense: Sometimes in politics, an agitator is one who intentionally excites and animates others about an important or controversial issue and urges them to protest.
2. An apparatus for shaking or stirring: The washing machines in Germany do not have an agitator like in Canada.

A person or something that diminishes or moderates an ailment or problem : The therapist was a great alleviator of Patrick's back pain.

The new tunnel under the river will be a wonderful alleviator of the traffic going across the river on the bridge.

1. Someone who goes from place to place; a walker: Jane was a regular ambulator for several times each day.
2. An instrument for measuring distances: The surveyor was using an ambulator consisting of a wheel to roll along over the ground with a dial plate to measure the distance traveled from one point to another one.

A person who removes or cuts off a part of or all of the limb of the body: An amputator is a physician who has specialized in surgery: Joseph Lister was a famous English amputator who used antiseptics for the first time when operating on patients.

1. Someone who makes movies that use motion, or who provides technical or artistic skills that are needed to produce movements: Mr. Long was an animator who created lively cartoons for children which could be seen on TV.
2. Someone or something that makes things lively, exciting, or interesting: Ted seemed to be an animator who was full of energy when he talked about his hobby and it sounded so thrilling and inspiring to be a mountain climber like he was.