Key terms & definitions

A reported experience during perceived or actual closeness to death, sometimes involving an apparent separation from the body or encounters with other people.

A cloud of gas and dust in space from which a star can form.

A being that cannot fail to exist and does not depend on anything else for its existence.

A Bible passage, commonly from Psalm 51, used as a reading test to claim benefit of clergy; memorising it could allow a non-clergyman to pass.

Magic involving the dead, particularly attempts to summon them or communicate with their spirits.

Death of cells or tissues in a living organism.

A newly emerging economy: a country experiencing rapid economic development and increasing industrial activity.

Something essential for living, such as food, shelter or necessary healthcare.

Restrictions on the amount of commercially released recorded music a broadcaster could play.

Changing a number’s sign while keeping its magnitude unchanged; for example, changing +5 to −5.

The state of an object that has gained electrons and therefore has more electrons than protons.

A relationship in which one variable generally decreases as the other increases.

A relationship in which higher values of one variable tend to occur with lower values of another.

A relationship in which y generally decreases as x increases.

An association in which larger values of one variable tend to occur with smaller values of the other.

An association in which higher values of one variable tend to occur with lower values of the other.

A situation in which the debt owed on a property is greater than the property's current value.

A control process in which a departure from the normal level causes responses that oppose the change and restore conditions towards normal.

A control mechanism in which a change away from a normal level triggers a response that opposes the change, bringing the level back towards its normal range.

Information that identifies what a performer did incorrectly so that they can correct it.

A power representing a reciprocal: for example, $x^{-3}=\frac{1}{x^3}$, with .

A negatively charged ion formed when an atom gains one or more electrons.

A process in which an initial loss of jobs, income or population causes further falls in spending, employment and services.

A reinforcing sequence in which lost jobs or spending reduce demand for other businesses and services, causing further decline.

A number less than zero, written with a negative sign, such as $-5$.

The reciprocal of a number with its sign changed; the negative reciprocal of $m$ is $-1/m$.

A penalty or expression of disapproval in response to behaviour that breaks a group’s rules or expectations.

A mental framework containing unfavourable beliefs about oneself, which can bias the interpretation of experiences.

A distribution with a longer tail towards lower values, usually with most values concentrated towards the higher end.

An area of the frame that is relatively empty, which can draw attention to a subject or suggest isolation.