Top Definition
When a thread on a message board starts as one thing and evolves into something else.
This thread started as a discussion of health care and now it's just pictures of hot nurses. I approve of this threadvolution.
by Rajun Caucasian January 22, 2010
Free Daily Email

Type your email address below to get our free Urban Word of the Day every morning!

Emails are sent from We'll never spam you.