This book is the published version of the thesis of Dr. Ayo Yusuff which he submitted to the School of Postgraduate Studies, University of Lagos, Nigeria in October 2008. Using a plethora of data critically elicited from a wide range of sources, the book demonstrates the capacity of the Yoruba language to handle modern concepts and thoughts. It attempts to resolve the problem as to whether foreign concepts and modern thoughts can be expressed in the Yoruba language. Apart from highlighting the various strategies for expanding the Yoruba lexicon, it relates such to other very relevant fields of Linguistics, namely Phonology, Morphology and Syntax. While unifying both purposeful and spontaneous efforts in Yoruba Language Engineering, it also provides guidance as to how to choose among fabricated lexical items. It contains viable suggestions and recommendations on the way forward for a scientific and technologically based Yoruba lexicon.