shake down
shake down  {v. phr.}
1. To cause to fall by shaking. 
He shook some pears down from the free.
2.  {informal}
To test, practice, get running smoothly (a ship or ship's crew). 
The captain shook down his new ship on a voyage to the Mediterranean Sea.
3.  {slang}
To get money from by threats. 
The gangsters shook the store owner down every month.
Categories: 
 
Source: A Dictionary of American Idioms
