Weddingbee boards

Technically a tux would not be appropriate morning dress for a man, since morning dress incorporates the cutaway coat with a black or grey tie.  A "morning suit" would simply be a grey suit, and I assume that the main reason for using the term would be to try to avoid very casual dress and also because requiring formal dress would not be appropriate in the morning.  So a black tux (being formal dress, and black) would not really be appropriate.  If your guy doesn't have a suit, it's likely that a nice pair of dress pants and a sports coat with a tie would be the closest approximation.

At events where men wear formal morning dress (such as the Royal Ascot), women generally wear a day dress, hat, and gloves.  I wouldn't wear a long dress in the morning, but a formal tea length dress (NOT a cocktail dress) would be appropriate.  I would think that you can dispense with the hat and gloves unless you just love the drama.  I doubt that most femaleguests will go out and buy a hat and gloves just for this occasion, just as I doubt that most men will go out and buy a cutaway coat.