from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A dark blue dyestuff, the first to be commercially produced.
from the GNU version of the Collaborative International Dictionary of English
- n. A dark blue substance obtained from wood tar. It consists of hydrocarbons which when oxidized form the orange-yellow eupittonic compounds, the salts of which are dark blue.
from The Century Dictionary and Cyclopedia
- n. A blue substance used in dyeing, originally produced from the tar of beech-wood.
Ancient Greek pitch + beautiful: compare French pittacale. (Wiktionary)