noun

• A technique that uses light and shade, or the relationship between the visible vs. hidden to create depth, definition and dimension
• In art, chiaroscuro refers to the use of strong contrasts between light and dark, a technique that adds dramatic impact and creates a sense of three-dimensionality in a two-dimensional work by skilfully arranging or treating light and shadow.

etymology

Mid-17th century: from the Italian word chiaro meaning ‘clear, bright’ (from the Latin clarus) + oscuro, meaning ‘dark, obscure’ (from Latin obscurus).

noun

• plural form of medium = an agency or means of doing something e.g.” medium for job creation” or ” medium of exchange”
• the material or form used by an artist, composer, or writer e.g. paint, print, film
• the midway point or in-between state between two extremes; a reasonable balance: “reaching a happy medium between style and substance”
• how something is communicated or expressed e.g. ‘the medium is the message’
• mainstream forms of mass communication (broadcasting, publishing, and the internet) regarded collectively