cornerstone• As a cornerstone, Galvin established the character and culture of the company he wished Motorola to be.• Whatever his manias, his music remains a cornerstone of the classicalrepertoire.• Local authority directlabour organisations are the cornerstones of training in construction.• All the eulogies he offered seemed to be for the men who had been the cornerstones of the neighborhood.• The theory of platetectonicsexplains these phenomena and is commonly regarded as one of the cornerstones of modern geophysics.• In the past, one of the cornerstones of the economic argument for conservation was its value to tourism.• Perhaps an alliance with the East Angles was the cornerstone of Aethelbald's ascendancy.• The Liturgy for that Sunday was the cornerstone of both prayer and reflection.