Merriam-Webster's Word of the Day for November 19, 2008 is:

deportment • \dih-PORT-munt\  • noun
: the manner in which one conducts oneself : behavior

Example sentence:
The school expects students to dress in proper attire and maintain a respectful level of deportment throughout the day.

Did you know?
"Deportment" evolved from the verb "deport," meaning "to behave especially in accord with a code," which in turn came to us through Middle French from Latin “deportare,” meaning "to carry away." (You may also know "deport" as a verb meaning "to send out of the country"; that sense is newer and is derived directly from Latin “deportare.”) "Deportment" can simply refer to one's demeanor, or it can refer to behavior formed by breeding or training and often conforming to conventional rules of propriety: "Are you not gratified that I am so rapidly gaining correct ideas of female propriety and sedate deportment?" wrote 17-year-old Emily Dickinson to her brother Austin.