From Longman Dictionary of Contemporary Englishrhombusrhom‧bus /ˈrɒmbəs $ ˈrɑːm-/ noun [countable] technicalCF a shape with four equal straight sides, especially one that is not a square
Examples from the Corpus
rhombus• They are situated at the four points of a rhombus.Origin rhombus (1500-1600) Latin Greek rhombos 