1. Distillation or separation of the volatile constituents of a substance.
2. Exclusive mental concentration; absent-mindedness.
3. A malocclusion in which the teeth or associated structures are lower than their normal occlusal plane.
4. The selection of a certain aspect of a concept from the whole. : a concept or idea not associated with any specific instance; “he loved her only in the abstract–not in person” [syn: abstract] 2: the act of withdrawing or removing something 3: the process of formulating general concepts by abstracting common properties of instances [syn: generalization, generalisation] 4: an abstract painting 5: preoccupation with something to the exclusion of all else [syn: abstractedness] 6: a general concept formed by extracting common features from specific examples
1. Generalisation; ignoring or hiding details to capture some
kind of commonality between different instances. Examples are
abstract data types (the representation details are hidden),
abstract syntax (the details of the concrete syntax are
ignored), abstract interpretation (details are ignored to
analyse specific properties).

2.
Parameterisation, making something a function
of something else. Examples are lambda abstractions (making
a term into a function of some variable), higher-order
functions (parameters are functions), bracket abstraction
(making a term into a function of a variable).

Opposite of concretisation.