The term "slicker" can have multiple meanings depending on its context.
1) In a general sense, it could refer to something that is smooth and polished in appearance or function. For example, a slick car engine runs very efficiently due to its sleek design.
2) It could also describe an object with a slippery texture, such as a slick rock surface which makes climbing difficult.
3) In the world of hair care products, "slicker" is often used in reference to brushes or combs that have closely spaced teeth designed to detangle and smooth out hair. These tools are commonly referred to as "slicker brushes."