coming after ...1645 obs. rare
from post (prefix) + -ventional (in preventional adj.)
FIRST DOCUMENTED USE
1645 - see EXAMPLE below
"...In the full-Moon postventionall to the Comet, 1618, the Sun was in the tenth degree of Sagittarius. In the second Conjunction of Saturn and Jupiter, 1623, the almost degree of this present Lunation did mediate heaven. King Charles went into Spain that yeer..."
From: The Starry Messenter; or An Interpretation of that Strange Apparition of Three Suns Seens in London, 19. Novemb. 1644.
being the Birth Day of King Charles
- William Lilly