A questioning or examining that is often harsh or severe.
The President's choice for the cabinet position turned down the appointment, fearing that the confirmation hearings would turn into an inquisition into her past.
While inquiry is a general term and can apply to almost any search for truth, inquisition suggests an ongoing search for hidden facts that is thorough and involves long and harsh questioning. Originally inquisition had about the same meaning as inquiry, but our current use is very much influenced by the Spanish Inquisition, an ongoing trial which began in the Middle Ages and was conducted by church-appointed inquisitors who sought out nonbelievers and Jews and sentenced thousands of them to torture and to burning at the stake. Because of this historical connection, the word today almost always means ruthless questioning conducted with complete disregard for human rights.