Sentence:  "You'll make yourself disliked on board!" / "By von Heumann merely." / "But is that wise when he's the man we've got to diddle?" / "The wisest thing I ever did. To have <WSD>chummed</WSD> up with him would have been fatal -- the common dodge." 
Meaning of the word marked with <WSD> tags:  To make friends; to socialize.