Slate is a type of fine-grained metamorphic rock that is commonly used for roofing, flooring, and other construction purposes. It can also refer to a flat piece of slate used as a writing surface. The term "group of runners" does not provide clear context related to the definition of slate.
Note: The provided meaning of the answer is for the latest New York Times crossword puzzle clue: Shade of gray. Explanations are generated by AI and may be inaccurate.