Yellow Knight

Let's assume Company XYZ wants to acquire Company ABC. Company ABC feels that Company XYZ is a hostile bidder and will ruin the company. As a result, Company ABC's directors go on the offensive and tell the shareholders that a sale to Company XYZ would not be a good thing.

Company XYZ, fearing a legal battle and little support from shareholders on both sides, backs off. That is, it becomes a yellow knight. Instead, Company XYZ comes back to Company ABC on more friendly terms and proposes a merger.