ghost [OE] In Old English gāst meant ‘a person’s spirit or soul’. This sense is preserved in to give up the ghost, ‘to die’, the original idea being of the soul as the source of life, although it now often refers to equipment that has broken down beyond repair. The ghost in the machine refers to the mind viewed as distinct from the body. It was coined by the British philosopher Gilbert Ryle (1900–76) in The Concept of the Mind (1949), and was also the title of a book in 1967 by polymath Arthur Koestler (1905–83). See also aghast.