Definition of perilune in US English:

perilune

noun

  • The point at which a spacecraft in lunar orbit is closest to the moon.

    The opposite of apolune
    • ‘SMART - 1 reached its closest point to the lunar surface so far - its first ‘perilune’ - at an altitude of about 5000 kilometres at 18: 48 Central European Time on 15 November.’

Origin

1960s: from peri- ‘around’ + Latin luna ‘moon’, on the pattern of perigee.

Pronunciation

perilune

/ˈperəˌlo͞on//ˈpɛrəˌlun/