Willow is the English word for the tree (Salix), known for its long flexible branches and association with watersides. In English folklore the willow was a tree of mourning — willow branches were carried at funerals — but also of healing: willow bark is the natural source of salicylic acid, the active compound in aspirin.
Willow's use as a girl's name is recent. It rose into the U.S. top 100 only in the 2010s and continues to climb. Pink and Carey Hart named their daughter Willow in 2011. Will Smith and Jada Pinkett-Smith's daughter Willow Smith is a singer who has kept the name highly visible.
Willow reduces to one — the number of independence, originality, and quiet leadership.