Willowish is an adjective used to describe someone or something that is slender, graceful, and flexible, much like a willow tree's fine branches. Some synonyms for willowish include supple, pliant, lithe, graceful, and svelte. These words all evoke a sense of delicate elegance, of something that moves easily and smoothly without being constrained by rigidity or stiffness. Other suitable alternatives include slender, sinuous, slim, and lissome. Willowish is a relatively uncommon term, but these synonyms are more widely used and can convey a similar aesthetic and meaning.