The term 'Eye Enhancer' refers to a type of makeup product that is used to define and enhance the eyes. The crossword solution for this term is 'LINER, ' which is a type of eye makeup that is used to line the eyes and create a more dramatic look. LINER can be applied to the upper and lower lash lines, as well as the waterline, to create a variety of looks. It is available in a variety of colors and finishes, from matte to shimmery, and can be used to create subtle or bold looks.