Definition of periaster in English:

periaster

noun

Astronomy
rare
  • Periastron.

Origin

Mid 19th century; earliest use found in John Pringle Nichol (1804–1859), astronomer and political economist. From peri- + ancient Greek ἀστήρ star, after perigee, perihelion, etc. Compare French périastre.

Pronunciation

periaster

/ˌpɛrɪˈastə/