What's a colonnade? My girlfriend is freaking me out with stories of her dream wedding where she walks down a colonnade. I know this is the least of my problems, but I'm curious.

A colonnade is a series of columns set at regular intervals, flanking a walkway and usually supporting a roof or series of arches. (For a wedding, the columns are often wrapped with garlands of flowers.)

In Edith Wharton's Ethan Frome, a type of colonnade decorates the local post office:

If you know the post-office you must have seen Ethan Frome drive up to it, drop the reins on his hollow-backed bay and drag himself across the brick pavement to the white colonnade: and you must have asked who he was.