Definition of phacoid in English:

phacoid

noun

Geology
  • A lens-shaped body of distinct composition in a rock, especially an inclusion of feldspar or quartz.

Origin

Mid 19th century (in an earlier sense). From phaco- + -oid, after ancient Greek ϕακοειδής having the shape of a lentil or lens, in Hellenistic Greek especially applied to the lens of the eye (also recorded as a Greek word in Latin context in Vesalius).

Pronunciation

phacoid

/ˈfakɔɪd/