Douglas Harper's Etymology Dictionary
type of hawk that is believed to prey on domestic fowl, 1802, American English. Figuratively, from the secondary senses of both words, "public person who advocates war but who declined significant opportunity to serve in uniform during wartime," at least 1988, American English. From chicken (n.) + hawk (n.).
Wiktionary
n. 1 (context archaic English) Any of the North American hawk species (Cooper's hawk, sharp-shinned hawk and red-tailed hawk), or counterparts elsewhere, mistakenly believed to be pests. 2 (context British US gay slang English) An adult male preferring younger male sexual partners. 3 (context pejorative political slang English) An advocate of war or military action who is avoiding personal military service, or avoided it in the past.
WordNet
n. nontechnical term for any hawks said to prey on poultry [syn: hen hawk]
Usage examples of "chicken hawk".
Francis considered his own talent on the ball field of a hazy, sunlit yesterday: how he could follow the line of the ball from every crack of the bat, zap after it like a chicken hawk after a chick, how he would stroke and pocket its speed no matter whether it was lined at him or sizzled erratically toward him through the grass.
That when I came into the kitchen, my mother was cooking chicken and dumplings and my father was paying bills and after they ignored me long enough my grandpop took his nose out of the newspaper and told me that a chicken hawk had flown down from the sky and taken Lucky away.