to become familiar with a new situation and begin to work well in it; to search a person or place in a very thorough way
informal
to become familiar with a new situation and begin to work well in it
shake sb / sth down
to search a person or place in a very thorough way
shake sb / sth down
to threaten sb in order to get money from them
Definitions from the Oxford Advanced Learner's Dictionary, 9th edition