Definition of orthophyre in US English:

orthophyre

noun

Geology
rare
  • A porphyritic rock containing phenocrysts chiefly of orthoclase in a feldspathic groundmass.

Origin

Mid 19th century; earliest use found in American Naturalist. From French orthophyre from ortho- ortho- + -phyre (in porphyre).

Pronunciation

orthophyre

/ˈɔːθə(ʊ)fʌɪə/