cross section

¹

[ kraws sek-shuhn, kros ]

noun

1. a section made by a plane cutting anything transversely, especially at right angles to the longest axis.
2. a piece so cut off.
3. a photograph, diagram, or other pictorial representation of such a section.
4. the act of cutting anything across.
5. a typical selection; a sample showing all characteristic parts, relationships, etc.:

   a cross section of American opinion.

6. Surveying. a vertical section of the ground surface taken at right angles to a survey line.
7. Also called nuclear cross section. Physics. a quantity expressing the effective area that a given nucleus presents as a target to a bombarding particle, giving a measure of the probability that the particle will induce a reaction.

cross-section

²

[ kraws-sek-shuhn, kros- ]

adjective

1. Also cross-sectional. of or relating to a cross section.

verb (used with object)

1. to make or divide into a cross section.

cross section

noun

1. maths a plane surface formed by cutting across a solid, esp perpendicular to its longest axis
2. a section cut off in this way
3. the act of cutting anything in this way
4. a random selection or sample, esp one regarded as representative

   a cross section of the public

5. surveying a vertical section of a line of ground at right angles to a survey line
6. physics a measure of the probability that a collision process will result in a particular reaction. It is expressed by the effective area that one participant presents as a target for the other

cross section

1. In particle physics, an expression of the probability of the occurrence of an event, typically the scattering of subatomic particles, over a given area.

Derived Forms

• ˌcross-ˈsectional, adjective

Word History and Origins

Origin of cross section¹

First recorded in 1825–35

Origin of cross section²

First recorded in 1875–80

Example Sentences

"By amplifying the fusion cross section, more power can be produced from the same amount of fuel," said Parisi.

From Science Daily

“Hopefully our country can get back to that. The Owens Valley, and Inyo County in particular, is a perfect cross section of America.”

From Los Angeles Times

“These days we’ve got a truly diverse cross section of South Africa coming to the event, all ages, races, and genders,” says rAge project director, Michael James.

From BBC

Mom held up my name badge, which was a cross section of a tree on a necklace of twine.

From Literature

Some models predict that dark matter has a certain mass or cross section, which is the probability of a specific event occurring due to the interaction of particles.

From Science Daily

Related Words

• random sample
• sampling