Key terms & definitions

A statement of the meaning of a term that includes the features needed to distinguish it from other things.

A chemical used to remove leaves from plants and trees, reducing the cover provided by vegetation.

The removal of forest, often to make land available for farming or other uses.

The large-scale clearing of trees from an area of forest.

The clearing of forests, usually on a large scale, often to use the land for another purpose.

The clearing or removal of forests.

The clearing or loss of forests, for example when trees are removed for timber or farming and the forest is not replaced.

The amount or proportion of forest cleared over a stated period, often expressed in hectares per year or as a percentage per year.

A change in an object's shape or size caused by forces.

A change in an object's shape caused by forces, such as stretching, bending or compression.

Changing the shape of existing material by force, for example bending sheet metal.

Changing the shape of existing material, for example by bending, pressing or heating and forming it.

The process of rearranging fragmented files on a hard disk so that the parts of each file are stored together.

Software that reorganises fragmented files on a magnetic hard disk drive so that their parts are stored together, improving access speed.

A label used by the Nazis to condemn art, music and literature that they considered unacceptable or contrary to Nazi values.

A historical belief that individuals or societies could decline into a supposedly more primitive condition. It is not the same as Darwin’s theory of evolution.

A nineteenth-century belief that human beings or civilisation could decline into a supposedly more primitive condition. It is historical context, not an accepted explanation of criminal behaviour.

The removal of oil and grease from a surface so that a coating can adhere properly.

A unit of angular measure; one complete turn is $360^\circ$.

The highest power of the variable with a non-zero coefficient in a polynomial.

A unit of angular measurement. One complete turn is $360°$.

The level of precision used to state a value, such as a given number of decimal places or significant figures.

The fraction or percentage of acid particles that form ions when the acid dissolves in water.

The proportion of a population living in urban areas at a particular time, usually expressed as a percentage.

A Sikh expression meaning ‘victory of the cauldron and sword’: a commitment to providing food and defending justice.

The presentation or treatment of a person as less than fully human, for example as a machine, tool or weapon.

A net loss of body water that leaves too little water in the blood and tissues.

A reaction in which water is removed from a substance.

Excessive loss of body water that interrupts the normal functioning of the body.

A condition in which the body loses more water than it replaces and does not have enough water to function properly.