look up any word, like usuratonkachi:
 
1.
In formal business environments, employees are allowed to wear business casual clothes instead of suits on this last day of the work week. Sometimes given a theme, it is intended to alleviate stress and bolster employee morale.

In smaller companies where business casual is worn every day, this day should be called just "Casual Friday" when lower-quality clothes are allowed.

When in doubt, it is better to overdress than to wear clothes too casual, so as not to be reprimanded by the suits.

formal > business formal > business casual > casual
Business casual: Sweater, collar without a necktie, polo, vendor swag, blouse, black/brown/navy/gray trousers, pressed khakis.

Casual: Dockers, denim jeans, shorts, t-shirts, linen.
by Coell July 06, 2005
 
2.
The term used by places of buisiness that allow the employees a slackening of the dress code on the final day of the work week. Commonly known as "Biz Cas Fri". Well, not really.
"Oh, how I love to wear unique-colored pants and a belt full of metal squares rather than just plain khakis on BUSINESS CASUAL FRIDAY."
by Kaleb Matthews January 12, 2006
 
3.
The day when peolpe at the office wear free polo shirts they got from various software companies.
My favorite day of the week.
by SMD August 21, 2004