grey knight

noun

informal an ambiguous intervener in a takeover battle, who makes a counterbid for the shares of the target company without having made his intentions clearCompare black knight, white knight

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