cross-section

/K R AO1 S S EH1 K SH AH0 N/
noun
  1. 1

    A section formed by a plane cutting through an object, usually at right angles to an axis.

  2. 2

    A sample meant to be representative of a whole population.

  3. 3

    The probability that a particular nuclear reaction will take place.

Source: https://en.wiktionary.org/wiki/cross%20section, https://en.wiktionary.org/wiki/cross-section