cross section

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A section formed by a plane cutting through an object, usually at right angles to an axis.
2. n. A piece so cut or a graphic representation of such a piece.
3. n. Physics A measure of the probability that an encounter between particles will result in the occurrence of a particular atomic or nuclear reaction. Also called collision cross section.
4. n. Statistics A sample meant to be representative of a whole population.
5. n. Informal A variety; a diversity.

Century Dictionary and Cyclopedia

1. n. A section of something made by a plane passed through it at right angles to one of its axes, especially to its longest axis; a piece of some body cut or sliced off in a direction perpendicular to an axis of the body: as, a cross-section of a tree cut out to show the grain; a drawing of the cross-section of a ship.
2. n. The area of a section, of a bar, tube, rod, or other body, taken at right angles to its axis.

Wiktionary

1. n. A section formed by a plane cutting through an object, usually at right angles to an axis.
2. n. statistics A sample meant to be representative of a whole population.
3. n. physics The probability that a particular nuclear reaction will take place.

GNU Webster's 1913

1. n. a flat plane cutting through a three-dimensional object, usually at right angles to the longest axis of the object.
2. n. any visual representation of a cross section{1}, showing the internal structure of the object in the plane of the cross section.
3. n. a thin slice of an object made by cutting it transversely.
4. n. a representative sample of a complex group.
5. n. (Physics) a measure of the probability that a nucleus will interact in a specified way with a bombarding particle, expressed as the effective area that the nucleus presents to the particle; -- called also nuclear cross section.
6. v. to create one or a series of cross sections{3} by cutting (an object) into thin slices.

WordNet 3.0

1. n. a section created by a plane cutting a solid perpendicular to its longest axis
2. n. a sample meant to be representative of a whole population
3. n. (physics) the probability that a particular interaction (as capture or ionization) will take place between particles; measured in barns
4. adj. representing a plane made by cutting across something at right angles to its length