abdominal paracentesis insertion of a trocar through a small incision and into the peritoneal cavity to remove ascitic fluids or inject a therapeutic agent. This is most often done to remove excess fluid in a patient with cirrhosis of the liver. Called also abdominocentesis and peritoneocentesis.
Abstraction is the act of representing essential features without including the background details or explanations. In the computer science and software engineering domain, the abstraction principle is used to reduce complexity and allow efficient design and implementation of complex software systems.
Abstract and concrete are classifications that denote whether a term describes an object with a physical referent or one with no physical referents. They are most commonly used in philosophy and semantics. Abstract objects are sometimes called abstracta (sing. abstractum) and concrete objects are sometimes called concreta (sing. concretum). An abstract object is an object which does not exist at any particular time or place, but rather exists as a type of thing, i.e. an idea, or abstraction.