/pawr"feuh ree/ , n. , pl. porphyries .
1. a very hard rock, anciently quarried in Egypt, having a dark, purplish-red groundmass containing small crystals of feldspar.
2. Petrol. any igneous rock containing coarse crystals, as phenocrysts, in a finer-grained groundmass.
[ 1350-1400; ME porfurie, porfirie porphyreum, alter. of L porphyrites porphyrítes porphyry, short for porphyrítes líthos porphyritic (i.e., purplish) stone, equiv. to pórphyr ( os ) PURPLE + -ites; see -ITE 1 ]