Hit & Run: Chickenhawk Henpeck Begins:
“Near as I can tell, he means that unless we fight in the military, we have no business commenting on it.” Actually, [the word chickenhawk] refers to people who actively sought to avoid military service (or who made sure they got cushy assignments), like when Cheney and Delay got repeated deferrals, or when Bush jumped the line to get into the “Champagne Regiment.” People who’ve had no dealings whatsoever with the military can’t fairly have it held against them, but people who do their damnedest to make sure other people, and only other people, get put in harm’s way are despicable.
The comments to this post got off topic pretty quickly, it seemed, as some folks took more offense at the use of word chickenhawk than at the obscenity of this war the chickenhawks wanted so badly. I would further refine the definition to mean those who actively sought to avoid service in a war they supported and have continued to support armed actions without putting themselves in harm’s way.
<update> Wikipedia has a similar definition, with more detail.