- Royal Institute of British Architects.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- (in Islam) interest or usury, as forbidden by the Koran
C21: from Arabic al-Riba, literally: to excess or increase
- Royal Institute of British Architects
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012