Here's a list of the most important keywords and philosophical concepts of Negative Dialectics. Note that Adorno didn't invent all the below terms, but does put a unique spin on many of the traditional Marxian categories:
Appearance [Schein]. The German word means "appearance", "semblance", and also a "bill" or "financial note". Adorno uses it as a way of diagnosing the tendency of late capitalism to market or advertise everything in sight -- not just cultural works, but mundane things like news conferences, statements by the chair of the Federal Reserve, memos at the office, the set design of CNBC's market updates, and "PR" or public relations in general.
Bane [Bann]. The inescapable objective condition or existential enclosure of the capitalist world-system. The German word literally means "spell", but is translated as "bane" for two very good reasons: first, the whole discourse of fantasy and sci-fi literature has been completely incorporated into the information culture (programmers are "wizards", unpleasant individuals on listservs are "trolls", etc.). "Baleful spell" comes closer, but is not quite as good as the objectively malign "bane", simply because Adorno is describing a universal state of affairs, which limits all your choices and potential positions from the very beginning; literally, the weight of the world on the individual subject, something which is no joke in this multinational age.
Constellation [Konstellation]. Walter Benjamin first formulated the notion of the constellation, which forms one of the building-blocks of Adorno's thought. In its simplest definition, the constellation is multinational form: the arrangement or configuration in which a variety of concepts, models, ideas or other materials takes shape. These arrangements are very delicate; the movement of each element changes the entire configuration. Note further that one constellation can impinge or influence another one, across periods of history as well as within the same temporal frame.
Dialectics [Dialektik]. The thought-form characteristic of capitalism, which can be described as a thought which ceaselessly reflects on itself, which is in ceaseless motion, which constantly dynamizes itself and sets the objects of its cognition in motion in order to comprehend and operate in the dynamic society it lives in. This doesn't mean that it's always consistent or never gets caught in its own contradictions, but that it moves through these contradictions, treating them as productive problems to be worked through, and which, once solved, open up still further, more complicated problems.
Dialectics of disassembly [Dialektik des Zerfalls]. Demystificatory thought, which seeks to decode or disassemble the superficial appearances of objects and things, and diagnose the movement of history behind these things, which is never directly accessible as such.
Experience-content [Erfahrungsgehalt]. Adorno often talks about experience-content in conjunction with aesthetics and aesthetic experience, as something genuinely emancipating or liberating, but it isn't necessary associated with this. Rather, experience-content is something like the internalization of a vast number of experiences and memories, the constantly-growing pool of surplus consciousness, as it were, which constitutes the raw materials and bedrock substructures which ground our more specialized actions, cognitions and reflections. Adorno will often use this concept to access seemingly static, abstract or objective concepts, which have apparently shut themselves off from subjects, showing that even the most objective concept retains crucial traces of its subjective moment, which can then be read and historicized as an important diagnostic material in its own right.
Identity [Identitaet]. The basic notion of equivalence, that something is the same as (or expressible in terms of) something else, which is a fundamental feature of market societies based on exchange-value, i.e. that everything has a value only in relation to other commodities, which are hooked up in vast networks of production and distribution. Every identity is based on lots of other identities: money is useless without a banking system, which is useless without the commodities which people buy and sell, which is useless without money; instead, each one of these features has to coexist, simultaneously, for the whole thing to work (which is why it isn't terribly surprising that it took human beings thousands of year to create functioning markets, or that the capitalist world-system developed only after a very long and complex historical process). It's worth pointing out that Adorno uses the term in both its subjective and objective senses; living subjects have identities, of course, ranging from gender and age to national citizenship and professional affiliation, but the same logic of comparability applies to commodities, too: think of the way the average computer system is always identified as having a certain microprocessor, a certain amount of RAM, is produced by a certain company, etc. Those are all metrics of identity, which enable you to figure out the relative worth of one computer versus another. Adorno's crucial point here is that whereas living subjects have all sorts of identity-politics, so do objects: everything from industrial policies to trade agreements, and from health and safety labels to export subsidies.
Intuition [Anschauung]. This is a philosophical term handed down by Kant which literally means "intuition", and refers to the subjective apprehension of some sort of coherent object, situation or state which forms the raw material for its concept or naming, as opposed to the still more inchoate sensory impressions, sensations or fleeting states of mind which make up that apprehension. This may not sound important, but Adorno uses this concept to hammer away at Kant's juridical and legal antinomies, insisting that this process of apprehension -- something Kant glosses as the operation of the free will or subject -- is historical through and through, and that if you listen closely enough, you can decode genuine historical contradictions in those forms of apprehension.
Matter-at-hand [Sachverhalt]. General term for the matter under discussion, which Adorno frequently deploys as a conceptual sieve, capable of separating the ideological chaff from the materialistic truth-content of a given argument (not in order to toss the chaff aside - there are times when analyzing the ideology is more productive and useful than identifying the truth-content in question).
Model [Modell]. The model is a provisional construct, a bridge-mediation designed to move from the constellation to the non-identical around which a given identity has crystallized; it comes closest to what nowadays one might call a comparatist metric. Negative Dialectics offers three models for us: Kant's antinomies of freedom, Hegel's antinomies of natural history, and metaphysics in the dawning age of multinational capitalism.
Negative dialectics [Negative Dialektik]. Adorno's term for a post-national or multinational dialectics, i.e. a mode of thought capable of analyzing and decoding the world of post-Cold War, multinational capitalism.
Nomothetism [Gesetzmaessigkeit]. This term literally means "lawfulness" or "law-abiding character", but Jameson's Latinate translation is the best single translation one could hope for. It refers not so much to the lawful character or external sets of laws a society might have, so much as the immanent juridicality of societies based on exchange, i.e. the fact that they're permeated top to bottom by concepts of property, legal titles, claims, counter-claims, etc.
Non-identity [Nicht-identitaet]. One of the most subtle and difficult of Adorno's concepts; it doesn't just mean the opposite of identity, that is to say, the non-equivalent, or what doesn't fit into certain categories, which is usually just a metaphor for a different identity which isn't the same as the first identity, but refers to what escapes or eludes every sort of identity, but which nevertheless exists in the shadow or penumbra of identity, as the fleeting reminder or glimpse of unrealized possibilities, of what that identity locked out, excluded, or can't quite become. To use an egregiously inaccurate scientific metaphor, identity and non-identity relate to each other like the particle-antiparticle pairs of quantum mechanics, which exist only in relation to each other.
Spirit [Geist]. One of Hegel's leading concepts, Geist literally means "spirit" or "mind", and was the historic forerunner and model for Marx's mature concept of capital. Adorno uses the term as a heuristic or index of the internalized subjectivity or interiority of
individuals in capitalist societies, something closely tied to the experience of marketization.
Total system [System, Gesamtsystem]. Though one of Adorno's most-quoted concepts, this is actually one of his least-used terms, simply because "the system" simply means capitalism, a world-system based on the constant expansion of accumulation. One of the consequences of the Wall Street Bubble is that one can at last use the word "bourgeoisie" in a serious way, i.e. not as an epithet but as a descriptive term for the tiny multinational elite of industrialists, bankers, CEOs, stockholders and institutional chieftains who collectively own, operate and manage the productive assets of the world-system.