WHETSTONE-SLATE, WHET-SLATE noun Novaculite or coticular shist, a variety of slate used for sharpening instruments of iron. The light green colored variety from the Levant is the most valuable. It should be kept in a damp place, that it may not become too dry and hard.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI