RHOMBUS Meaning of RHOMBUS in English [ 'rɒmbəs ]■ noun ( plural ~es or rhombi -bʌɪ ) Geometry a quadrilateral whose sides all have the same length.OriginC16: via L. from Gk rhombos . Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004