Slate-pencil is a writing tool that was commonly used in the past for writing on a slate. However, with the introduction of modern technology, this writing instrument has become less popular. Nevertheless, there are still numerous synonyms for slate-pencil that one can use in their writing. These synonyms include graphite, charcoal, lead, and nib. Graphite is a popular alternative for slate-pencil as it delivers clear, concise lines that are suitable for writing and drawing. Charcoal is another great substitute as it also produces dark and striking lines that are easy to read. Lead and nib are also excellent options for anyone looking for a writing tool that is both efficient and durable.