(countable) A noun "contrast" represents a difference in lightness, brightness, and/or hue between two colors that can be measured and adjusted, or a control on a television that regulates the amount of contrast in displayed images.

(countable) A difference between two objects, people or concepts.

(countable) Something that is opposite of or strikingly different from something else.

(countable, uncountable, rhetoric) Antithesis.

(transitive) To set in opposition in order to show the difference or differences between.

(intransitive) To form a contrast.