transmission

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The act or process of transmitting.
2. n. The fact of being transmitted.
3. n. Something, such as a message, that is transmitted.
4. n. An automotive assembly of gears and associated parts by which power is transmitted from the engine to a driving axle. Also called gearbox.
5. n. The sending of a signal, picture, or other information from a transmitter.

Century Dictionary and Cyclopedia

1. n. The apparatus and mechanism for transmitting (with transformation) the revolutions of the motor-shaft in a motor-car to the driving-wheels. The motor should turn faster than the driving-wheels; it should turn at a uniform speed, while the wheels should have a varying speed; and the motor-shaft must turn in one direction, in internal-combustion motors, while the motion of the car must on occasion be reversed. The transmission may be by shafting and gears and clutches, or by sprocket-wheels and chains. The change of speed may be by a train of gears made variable by sliding one set lengthwise upon a short counter-shaft, so that the ratio of driving to driven gear will be different when different pairs are in gear; or the so-called planetary gear may be used, an epicyclic train or several of them, which go into action when the motion of the supporting casing which carries the rolling gears is constrained by a brake; or a multiplicity of clutches may be employed, with the teeth of the gears constantly in mesh; or a frictional transmission is possible. Reversing of the wheels is effected in an irreversible motor by throwing an additional idle or transmitting wheel into the train. The steam-motors do not require so much transformation mechanism, since they are always reversible and have in themselves a wide flexibility as to speed of the crank-shaft. In large cars, however, it is of advantage to have a high gear and a low gear, the latter for hill-climbing on bad roads and for other cases where high speed of the vehicle is undesirable and yet the power of the motor should not be unduly throttled. In the transmission is also usually included the compensating gear, enabling the two driving-wheels to traverse a different length of roadway, as on curves, without slipping at the contact of wheel and road surface.
2. n. The act of transmitting, or the state of being transmitted; transmittal; transference.
3. n. In biology, specifically, same as heredity.
4. n. In physics, a passing through, as of light through glass or other transparent body, or of radiant heat through a diathermanous body.

Wiktionary

1. n. The act of transmitting, e.g. data or electric power.
2. n. The fact of being transmitted.
3. n. Something that is transmitted, such as a message, picture or a disease; the sending of such a thing.
4. n. The passage of a nerve impulse across synapses.
5. n. An assembly of gears through which power is transmitted from the engine to the driveshaft in a motor car / automobile; a gearbox.

GNU Webster's 1913

1. n. The act of transmitting, or the state of being transmitted.
2. n. The right possessed by an heir or legatee of transmitting to his successor or successors any inheritance, legacy, right, or privilege, to which he is entitled, even if he should die without enjoying or exercising it.
3. n. The mechanism within a vehicle which transmits rotational power from the engine to the axle of the wheel propelling the vehicle; it includes the gears and gear-changing mechanism as well as the propeller shaft.
4. n. The process or event of sending signals by means of a radio-frequency wave from an electronic transmitter to a receiving device.

WordNet 3.0

1. n. communication by means of transmitted signals
2. n. the act of sending a message; causing a message to be transmitted
3. n. an incident in which an infectious disease is transmitted
4. n. the gears that transmit power from an automobile engine via the driveshaft to the live axle
5. n. the fraction of radiant energy that passes through a substance