World Wide Words: Gussied up
Originally Posted by colorcrazie
"Gussied up" (who was this Gussie?).
"Many people associate the term with more recent events. The American tennis player “Gorgeous Gussie” Moran is best remembered for appearing at Wimbledon in 1949 wearing frilly panties, which caused considerable interest and controversy. Could she have been linked to the phrase?"
The above is from the link for the origin of the term Gussied up. So now you know who Gussie is.