(noun)
a very thorough search of a person or a place
a shakedown by the police uncovered the drugs
(noun)
extortion of money (as by blackmail)
(noun)
initial adjustments to improve the functioning or the efficiency and to bring to a more satisfactory state
the new industry's economic shakedown
intended to test a new system under operating conditions and to familiarize the operators with the system
a shakedown cruise