Wearing slacks and a button down shirt. No need for a jacket or tie.
I'm glad this party is a semi-formal party, I can't afford a jacket or a tie!
by DJ Yeyo September 22, 2006
A slang term for a dress code prohibiting any apparel below the waist. Derived from a "Harold and Kumar" movie.
Macey loved to attend "semi formal" parties, especially when the place was packed tight.
by mrg4ce January 26, 2010