פְּגָם יְסוֹדִי
pegamyesodi
Formal HebrewMeaningA very big problem with something, right from its beginning or in its most important part.
HistoryThe word "pgam" first shows up in the Mishnah, a book of Jewish laws written about 1800 years ago. It means a mark that makes something not perfect. The word "yesodi" comes from the much older biblical word "yesod", which means the bottom part of a building that holds everything up. So, a "pgam yesodi" is a problem in the most important, bottom part of something.
Example
There is a basic flaw in this plan, it will not work.
