The term 'ADD LUSTER TO' can be completed with the crossword solutions REWAX, GLOSS, and SATYR. Rewax is a verb meaning to apply wax to something in order to make it shine or look more attractive. GLOSS is a noun referring to a smooth, shiny finish on a surface. SATYR is a noun referring to a mythical creature with the upper body of a human and the lower body of a goat, often associated with lustful behavior. Therefore, the phrase 'ADD LUSTER TO' can be interpreted as making something look more attractive, shiny, and lustful.