ˈpȯ(r)fərē, -ri noun
( -es )
Etymology: Middle English porfurie, from (assumed) Anglo-French porfirie, from Medieval Latin porphyrium, alteration of Latin porphyrites — more at porphyrite
1.
a. : an Egyptian rock consisting of feldspar crystals embedded in a compact dark red or purple groundmass much used by the ancient Romans — compare porphyrite
b. : any igneous rock of porphyritic texture regardless of its mineral composition
c. : an igneous rock containing two generations of the same mineral with the minerals of one generation usually distinctly larger than those of the other
d. : any of various igneous rocks without porphyritic texture that occur in connection with ores
2. obsolete : a porphyry slab ; especially : one used for triturating drugs
3. West : porphyry copper — usually used in plural