noun: (linguistics) Abbreviation of Proto-Central Algonquian. [(linguistics, historical) The formerly-hypothesized proto-language of the Central Algonquian languages, now recognized to be in effect Proto-Algonquian because Central Algonquian is not a genetic group.]
noun: (US, law) Abbreviation of Posse Comitatus Act. The U.S. law called "Posse Comitatus Act", 20 Stat. 152 aka 18 U.S.C. ยง 1385
noun: (aviation) Abbreviation of propulsion controlled aircraft (system/unit), an aircraft with a control system with two or more engines arrayed abreast, allowing descent, ascent, turns by adjusting the throttle control to the engines (sometimes used attributively).
noun: (statistics) Abbreviation of principal components analysis.
noun: (medicine) Abbreviation of patient-controlled analgesia; palliator.
noun: (anatomy) Initialism of posterior cerebral artery. [(anatomy) An artery that arises by the terminal forking of the basilar artery where it forms the posterior portion of the circle of Willis and passes on to supply the lower surfaces of the temporal and occipital lobes.]
