George Will is one of my favorite columnists, but it never fails that at least one word enters his column each Sunday and Thursday that I have no idea as to its meaning. Thursday's column (requires registration) includes: obstreperousness.
Obstreperous, according to Webster's New World Dictionary, Third College Edition:
adj. - to roar at; to make a loud noise; noisy, boisterous, or unruly, esp. in resisting or opposing.
So from now on, when I read Will's columns, I will include in my blog the word that I needed to look up - along with its definition.