from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A hydrate whose solid contains seven molecules of water of crystallization per molecule, or per unit cell
from The Century Dictionary and Cyclopedia
- n. In chem., a compound containing seven molecules of water, as common copperas in crystals, or ferrous sulphate heptahydrate (FeSO4.7H2O).
hepta- + hydrate (Wiktionary)