What is Inquisitio?

Legal Definition
In old English law. An inquisition or inquest. Inquisitio post mortem, an inquisition after death. An inquest of office held, during the continuance of the military tenures, upon the death of every one of the king's tenants, to inquire of what lands he died seised, who was his heir, and of what age, in order to entitle the king to his marriage, wardship, relief, primer seisin or other advantages, as the circumstances of the case might turn out. 3 Bl. Comm. 258. Inquisitio patriae, the Inquisition of the country; the ordinary jury, as distinguished from the grand assise. Bract, fol. 15b.
-- Black's Law Dictionary
Legal Definition
An inquisition; an inquest.
-- Ballentine's Law Dictionary