Cosmetic oil is a type of oil used in beauty products to moisturize and protect the skin. Jojoba oil, which has six letters, is a popular choice for cosmetic oil due to its ability to penetrate the skin and provide hydration. Aloe, with four letters, is another common ingredient in cosmetic oil, as it is known for its soothing and healing properties. ROUGE, with five letters, is also sometimes used in cosmetic oil, as it can help give the skin a healthy glow.