facetEnglishOxford Dictionary of Englishfacet /ˈfasɪt , ˈfasɛt / ▸ noun 1 one side of something many-sided, especially of a cut gem: a blue and green jewel that shines from a million facets. 2 a particular aspect or feature of something: a philosophy that extends to all facets of the business. 3 Zoology any of the individual units (ommatidia) that make up the compound eye of an insect or crustacean. – ORIGIN early 17th century: from French facette, diminutive of face ‘face, side’ (see face).