Dictionary.net

• the opportunity cost of the funds employed as the result of an investment decision; the rate of return that a business could earn if it chose another investment with equivalent risk

2006 - WordNet 3.0
By Princeton University

• the opportunity cost of the funds employed as the result of an investment decision; the rate of return that a business could earn if it chose another investment with equivalent risk

2011 - English Dictionary Database
By DataStellar Co., Ltd