1.  compendium(n = noun.communication) collection - a publication containing a variety of works;
is a kind of publication
has particulars: anthology, archives, compilation, digest

2.  compendium(n = noun.communication) - a concise but comprehensive summary of a larger work;
is a kind of sum-up, summary
Derived form adjective compendious₁

   A brief compilation or composition, containing the principal heads, or general principles, of a larger work or system; an abridgment; an epitome; a compend; a condensed summary. [1913 Webster]
"A short system or compendium of a science."

compendium, n. (pl. compendiums or compendia)
1 esp. Brit. a usu. one-volume handbook or encyclopaedia.
2 a a summary or abstract of a larger work. b an abridgement.
3 a a collection of games in a box. b any collection or mixture.
4 a package of writing paper, envelopes, etc.

Etymology:
L, = what is weighed together, f. compendere (as COM-, pendere weigh)

N  compend, compendium, abstract, precis, epitome, multum in parvo, analysis, pandect, digest, sum and substance, brief, abridgment, summary, apercu, draft, minute, note, excerpt, synopsis, textbook, conspectus, outlines, syllabus, contents, heads, prospectus, album, scrap book, note book, memorandum book, commonplace book, extracts, excerpta, cuttings, fugitive pieces, fugitive writing, spicilegium, flowers, anthology, collectanea, analecta, compilation, recapitulation, resume, review, abbreviation, abbreviature, contraction, shortening, compression, compendious, synoptic, analectic, abrege, abridged, variorum, in short, in epitome, in substance, in few words, it lies in a nutshell.

N  contraction, reduction, diminution, decrease of size, defalcation, decrement, lessening, shrinking, compaction, tabes, collapse, emaciation, attenuation, tabefaction, consumption, marasmus, atrophy, systole, neck, hourglass, condensation, compression, compactness, compendium, squeezing, strangulation, corrugation, astringency, astringents, sclerotics, contractility, compressibility, coarctation, inferiority in size, contracting, astringent, shrunk, contracted, strangulated, tabid, wizened, stunted, waning, neap, compact, unexpanded &c (expand), contractile, compressible, smaller &c (small).