Synonyms for Abstract:

adj.

absent (adjective)
lacking, Omitted, elsewhere, departed, missing, absent, void, nonexistent, vacant, out, away, truant, empty, no-show, gone, wanting.
academic (adjective)
hypothetical.
conceptual, theoretical (adjective)
ideal, hypothetical, transcendent, transcendental, complex, intellectual.
hypothetic (adjective)
hypothetic.
immaterial (adjective)
impalpable, unworldly, ethereal, eerie, imponderable, bodiless, unearthly, intangible, theoretical, spiritual, conceptual, supernatural, imaginary, incorporeal, immaterial, unsubstantial.
notional (adjective)
notional.
subjective (adjective)
nonobjective.

n.

nonconformist, deterministic, popular, utopian, central, orthodox. camp, aesthetic, painting, campy, accessible, symbolic, avant-garde, artsy-craftsy, baroque, artistic. find, remove, ascertain, extract, read up on, gather, uncover, separate, get, determine, find out, establish, withdraw, discover. encapsulate, decrease, sum up, generalize, summarize, rough out, boil down, condense. report, academic, speculative, round up, account. cartoon, collage, diptych, brief, canvas, caricature, doodle, daub, aquatint, words, bas relief. abstract (noun)
nobble, purloin, outline, nonobjective, hook, nonfigurative, ideational, filch, abstraction, pinch, notional, synopsis, ideal, cabbage, pilfer, conceptional, snarf, swipe, conceptual, technical, precis, lift, abstractionist, theoretical, sneak.
abstruse (noun)
difficult, involved, obscure, complex.
cognition (noun)
abstraction.
short document prepared from a longer one (noun)
condensation, compendium, summary, digest, synopsis, outline, abridgment, brief.
synopsis (noun)
excerpt, prospectus, abridgment, epitome, synopsis, overview, sketch, resume, precis, compendium, outline, digest, summary, condensation.
theoretical (noun)
intellectual, general.

v.

leave (verb)
leave, depart, omit, vacate, evacuate.
prepare short document from longer one (verb)
summarize, condense.
steal (verb)
lift, mug, blackmail, pilfer, grab, filch, pirate, shanghai, plunder, pocket, rustle, extort, poach, plagiarize, haul, loot, swipe, shoplift, hijack, embezzle, cop, holdup, burglarize, nip, palm, fleece, steal, defraud, heist, stickup, swindle, rob.
take away from (verb)
separate, extract, steal, withdraw, remove.

Other synonyms:

difficult, accessible, theoretic, transcendental, aquatint. hypothetical, transcendent, camp. speculative, academic. brief. steal
lift.
take
take.

Usage examples for abstract

  1. For a generation or two, however, these more abstract subjects have fallen into neglect; and, among those who plume themselves on being " practical," even into contempt. – Essays: Scientific, Political, & Speculative, Vol. I by Herbert Spencer
  2. The continental turn of mind is abstract the turn of the English and American mind is concrete. – The Future of International Law by Lassa Oppenheim