Meaning of post hoc, ergo propter hoc*

post hoc er•go prop•ter hoc

Pronunciation: (pōst' hōk', er'gō prōp'ter hōk" Eng. pōst' hok', ûr'gō prop't&schwar hok" er'gō), [key]
— Latin. Latin.
  1. after this, therefore because of it: a formula designating an error in logic that accepts as a cause something that merely occurred earlier in time.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.