To describe an onion, focus on its layered bulb structure, pungent aroma, sharp/sweet flavor, varied colors (yellow, red, white), and textures (crisp raw, soft cooked), mentioning its role as a fundamental ingredient due to sulfur compounds that cause tears. Use adjectives like pungent, sharp, sweet, crisp, layered, bulbous, golden, caramelized, diced, minced, raw, or cooked to capture its essence.