post hoc adjective 1adverb 1noun 1forms 3 adjective1 •After the fact.Our work on using research was post hoc rather than planned as an integral part of the original study. — 1986 adverb1 •After the fact.Ultimately, the wisdom of preemption will be judged post hoc. — 2005 noun1 •An instance of the post hoc ergō propter hoc fallacy, in which temporal order is confused with causation.or that it is altogether fair to accumulate the post hocs with their inevitable suggestion of propter — 1919 formspost hocs · more post hoc · most post hoc