Legend has it that “ugg” is short for “ugly” – so, “ugg boots” apparently meant “ugly boots.”
For decades, “ugg” was generic term used for sheepskin boots made in Australia. The word was so commonplace that it was found in Australian dictionaries, and ugg boots were also known as “ug” or “ugh” boots.
But in the United States, when people refer to “UGG boots,” they’re usually talking about the boots made by Deckers Outdoor Corporation, the parent company of “UGG Australia.”
So if you’re traveling the world and talking about footwear, it’s good to know that when the term “ugg boot” is used, it could be referring to an Australian-made sheepskin boot, or a popular brand name boot.
That’s just what I’ve overheard.