Slate-black is a descriptive word that usually describes a dark, bluish-gray color that resembles slate. However, there are several synonyms for slate-black that you can use to add variety to your vocabulary. For instance, you can use "charcoal-black" to describe a shade that is almost black but has a hint of gray or blue. "Jet-black" and "onyx-black" are often used to describe a shiny, glossy black. "Ebony-black" and "midnight-black" are also used to describe black shades that are almost pitch black. Other synonyms for slate-black include "graphite-black," "ashen-black," and "coal-black." By using these synonyms, you can add more depth and nuance to your color descriptions.