Ha, Found it !!! See below:

Did a Google search for "the wording and form of this standby has changed quite a bit over the centuries."

 

The answer:

 

This sentence means that the phrase or expression being discussed has evolved significantly throughout history, with its wording and structure changing considerably over time. 

 

• "Standby": In this context, "standby" refers to a well-known phrase or saying that people commonly use.