: the act of interrogating someone or something: such as
a
: a formal and systematic questioning
She conducted a skillful interrogation of the witness.
It was old-fashioned interrogation and eavesdropping that first led U.S. intelligence agents to the … plotters. Michael Isikoff
And during interrogation, instead of just listening for inconsistencies in what is said, agents are being taught to look for minute physical reactions on the faces of people being questioned. Ann Davis et al.
b
: the sending of an electronic signal intended to trigger a particular response from something (such as a transponder)
The airborne equipment measures the time between the interrogation and the return signal, and converts this time measurement into a mileage reading on our instrument panel, on either a dial or digital counter. Joseph W. Benkert