A white-tie occasion.    From Wordnet, Princeton University. 

Adjective : a white-tie embassy reception.    From Dictionary.com. 

That is at the White House, a white-tie and tails.    From Wordnik.com.  [CNN Transcript May 7, 2007] Reference

JOHN KING, HOST: Well, it's a white-tie affair, actually.    From Wordnik.com.  [CNN Transcript Mar 22, 2009] Reference

President Bush's approval ratings are in the toilet -- white-tie dinners aside.    From Wordnik.com.  [CNN Transcript May 7, 2007] Reference

If for no other reason than this will be President Bush's first white-tie dinner.    From Wordnik.com.  [CNN Transcript May 7, 2007] Reference

ROBERTS: Anita, this was the first white-tie event that this White House has held.    From Wordnik.com.  [CNN Transcript May 8, 2007] Reference

I went to a white-tie dinner at the White House once during the Clinton administration.    From Wordnik.com.  [CNN Transcript May 8, 2007] Reference

He'll host his administration's first ever white-tie dinner tonight, in honor of the queen.    From Wordnik.com.  [CNN Transcript May 7, 2007] Reference

Itzhak Perlman playing for those lucky enough to land a ticket to the rare white-tie affair.    From Wordnik.com.  [CNN Transcript May 8, 2007] Reference

Nodding to the white-tie and tails crowd, he quipped: "Some people call you the elite, I call you my base".    From Wordnik.com.  [So here's the new New Yorker cover.] Reference

ED HENRY, CNN CORRESPONDENT (voice-over): The queen arrived for this White House's first-ever white-tie dinner.    From Wordnik.com.  [CNN Transcript May 7, 2007] Reference

The impression their information gave me was that this is a bunch of white-tie, white-folk, elitist malcontents.    From Wordnik.com.  [ROVE COMES OUT] Reference

With pitch-perfect delivery and impeccable timing, who knew that a white-tie affair would actually loosen him up?.    From Wordnik.com.  [Will the Real John McCain Please Stand Up?] Reference

Let's rewind to yesterday, not the elaborate white-tie dinner, but actually the address in the garden before that.    From Wordnik.com.  [CNN Transcript May 8, 2007] Reference

At this moment, the Queen of England has just arrived at the White House for the state dinner, a white-tie state dinner.    From Wordnik.com.  [CNN Transcript May 7, 2007] Reference

MCBRIDE: She really thought if we were going to do a white-tie event in this administration, this would be the one to do.    From Wordnik.com.  [CNN Transcript May 8, 2007] Reference

Right now there's a white-tie state dinner honoring Queen Elizabeth II and guess who else is there -- our own Richard Quest.    From Wordnik.com.  [CNN Transcript May 7, 2007] Reference

I went to the toilet in the interval and became aware that a white-tie and tailed figure was standing in the next stall to me.    From Wordnik.com.  [Every living thing]

The televised white-tie ceremony in the Konserthuset, Stockholm's graceful concert hall, is otherwise closed to the general public.    From Wordnik.com.  [Partying With the Laureates] Reference

"Newsweek" 's Howard Fineman today told of a moment at an Al Smith Dinner, New York's white-tie gathering of Irish Catholic politicos.    From Wordnik.com.  [CNN Transcript Jun 13, 2008] Reference

In 1981, Ronald Reagan had eight white-tie affairs.    From Wordnik.com.  [News & Features from Minnesota Public Radio] Reference

The other wore white-tie and silly hats, and was bemused.    From Wordnik.com.  [Top stories from Times Online] Reference

They also have a white-tie dinner with other aristocrats.    From Wordnik.com.  [UUpdates - All updates] Reference

Both presidential candidates are scheduled to speak at the white-tie event Thursday.    From Wordnik.com.  [The Caucus] Reference

The debutantes celebrated with family and friends on March 13, 2010 at the white-tie fundraiser gala.    From Wordnik.com.  [Ventura County Star Stories] Reference

“This is a black-tie event, not a white-tie, “Mr. Lisi said.    From Wordnik.com.  [But of Corps! Marines, NYPD, Air Force Re-create 1920 Bacchanal] Reference

I wonder if Obama has not just changed men’s fashion permanently with his white-tie.    From Wordnik.com.  [Having a Ball - The Caucus Blog - NYTimes.com] Reference

Tonight, they're in white-tie.    From Wordnik.com.  [CNN Transcript Oct 16, 2008] Reference

Plus, inside the white-tie toast.    From Wordnik.com.  [CNN Transcript May 8, 2007] Reference

This white-tie dinner in the stateroom?.    From Wordnik.com.  [CNN Transcript May 7, 2007] Reference

It's a white-tie, very, very fancy dinner.    From Wordnik.com.  [CNN Transcript Jun 13, 2008] Reference