All 4 Uses of

abstract
in
The Count of Monte Cristo

As Danglars approached the disappointed lover, he cast on him a look of deep meaning, while Fernand, as he slowly paced behind the happy pair, who seemed, in their own unmixed content, to have entirely forgotten that such a being as himself existed, was pale and abstracted; occasionally, however, a deep flush would overspread his countenance, and a nervous contraction distort his features, while, with an agitated and restless gaze, he would glance in the direction of Marseilles, like one who either anticipated or foresaw some great and important event.†
Chpt 5-6

"What are you thinking of?" asked the abbe smilingly, imputing the deep abstraction in which his visitor was plunged to the excess of his awe and wonder.†
Chpt 17-18

"Who comes there?" cried the sentinel, who was less abstracted, and who saw by the lamp-light a shadow approaching his chief.†
Chpt 37-38

They might have remained much longer lost in one another, without any one noticing their abstraction.†
Chpt 69-70 *

Definitions:

(1) (abstract as in: abstract thought)
of a concept or idea not associated with any specific instance
(2) (abstract as in: read the abstract)
a summary; or to summarize -- especially academic writing
(3) (abstract as in: abstract art)
not imitating external reality or the objects of nature
(4) (abstracted as in: abstracted, so didn't notice)
lost in thought; or distracted by thoughts
(5) (abstracted as in: abstracted his wallet)
removed