Definition - What does Round mean?
Round is an adjective used to describe a wine which has a smooth, soft and supple texture.
Round wines have little or no tannin, and round wines that have no presence of tannin often fall into the category of "young" wines. These are wines which are ready-to-drink and cannot be aged.
WineFrog explains Round
A round wine is a general term that describes a wine which is easily appreciated by many wine consumers. These are wines which lack complexity, however, they are uncomplicated and still easy to enjoy.
The term "round", however, can be elaborated as well-rounded. The two should not be confused. A well-rounded wine describes wines that are complex and have been crafted well to display balanced notes of flavor, acidity, aroma and bouquet, tannin and finish.