Definition of sully

The word "sully" has its roots in Old French and Middle English. The verb "sullier" or "sulier" dates back to the 14th century and meant "to soil" or "to dirty." This sense of the word is still used today, as in "to sully one's reputation" or "to sully the air with pollution." But the word "sully" also has a less common, yet fascinating, historical origin. In the 15th century, a "sully" referred to a siege engine or a war machine used to batter down castle walls. This sense of the word was lost over time, but it's still related to the idea of damaging or defiling something, much like how a siege engine would breach a castle's defenses. So, in summary, "sully" originally meant "to soil" or "to dirty," but its history also includes a connection to damaging or defiling, as in breaching the defenses of a castle.