Sentence:  "No. But one, or both of those men, may prove to be worse. That second man was Addison Berg, and he's agent for a firm of submarine boat builders who are rivals of dad's. Berg has been trying to find out why we abandoned our intention of <WSD>competing</WSD> for the Government prize." 
Meaning of the word marked with <WSD> tags:  To be in battle or in a rivalry with another for the same thing, position, or reward; to contend