from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A very hard, dense, even-textured, silica-bearing sedimentary rock used in whetstones.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A form of chert, very rich in quartz, that has been used to make whetstones
from the GNU version of the Collaborative International Dictionary of English
- n. A variety of siliceous slate, of which hones are made; razor stone; Turkey stone; hone stone; whet slate.
from The Century Dictionary and Cyclopedia
- A very hard, fine-grained rock, used for hones: same as honestone. It is a very silicious variety of clay slate.
Latin novācula, razor + -ite1.(American Heritage® Dictionary of the English Language, Fourth Edition)