Using an inclusive term for something included, or vice versa; using something spoken of as the whole (hand for laborer) or vice-versa (the court for the judge).(adjective)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "synecdochic" in a sentence
"I realize I am being figurative -- not metaphoric, but synecdochic -- in saying you can count on meeting a Carrot at BEA2012."
"Heck, the word "liberal" - itself is, for some of those who stand on the other side of the red/blue divide, a synecdochic stand-in for "tax-and-spend homosexual-loving anti-Americans.""
"Political discourse, as practiced by Obama, McCain, and practically every other politician plopped in front of a microphone, is riddled with, mired in, crippled by, and sometimes derailed by synecdochic expressions."