1.  universe(n = noun.object) cosmos, creation, existence, macrocosm, world - everything that exists anywhere; "they study the evolution of the universe"; "the biggest tree in existence"
is a kind of natural object
has parts: celestial body, heavenly body, estraterrestrial body, extraterrestrial object
has particulars: closed universe, natural order, nature
Derived form adjective universal₁

2.  universe(n = noun.cognition) population - (statistics) the entire aggregation of items from which samples can be drawn; "it is an estimate of the mean of the population"
is a kind of accumulation, aggregation, assemblage, collection
has particulars: subpopulation

3.  universe(n = noun.cognition) universe of discourse - everything stated or assumed in a given discussion;
is a kind of cognitive content, content, mental object

   All created things viewed as constituting one system or whole; the whole body of things, or of phenomena; the to~ pa^n of the Greeks, the mundus of the Latins; the world; creation. [1913 Webster]
"How may I
Adore thee, Author of this universe
And all this good to man!" [1913 Webster]

universe, n.
1 all existing things; the whole creation; the cosmos.
2 all mankind.
3 Statistics & Logic all the objects under consideration.

Idiom:
universe of discourse Logic = sense 3.

Etymology:
F univers f. L universum neut. of universus combined into one, whole f. UNI- + versus past part. of vertere turn

N  world, creation, nature, universe, earth, globe, wide world, cosmos, kosmos, terraqueous globe, sphere, macrocosm, megacosm, music of the spheres, heavens, sky, welkin, empyrean, starry cope, starry heaven, starry host, firmament, Midgard, supersensible regions, varuna, vault of heaven, canopy of heaven, celestial spaces, heavenly bodies, stars, asteroids, nebulae, galaxy, milky way, galactic circle, via lactea, ame no kawa, sun, orb of day, Apollo, Phoebus, photosphere, chromosphere, solar system, planet, planetoid, comet, satellite, moon, orb of night, Diana, silver-footed queen, aerolite, meteor, planetary ring, falling star, shooting star, meteorite, uranolite, constellation, zodiac, signs of the zodiac, Charles's wain, Big Dipper, Little Dipper, Great Bear, Southern Cross, Orion's belt, Cassiopea's chair, Pleiades, colures, equator, ecliptic, orbit, astronomy, uranography, uranology, cosmology, cosmography, cosmogony, eidouranion, orrery, geodesy, star gazing, star gazer, astronomer, observatory, planetarium, cosmic, cosmical, mundane, terrestrial, terrestrious, terraqueous, terrene, terreous, telluric, earthly, geotic, under the sun, sublunary, subastral, solar, heliacal, lunar, celestial, heavenly, sphery, starry, stellar, sidereal, sideral, astral, nebular, uranic, in all creation, on the face of the globe, here below, under the sun, die Weltgeschichte ist das Weltergesicht, earth is but the frozen echo of the silent voice o, green calm below, blue quietness above, hanging in a golden chain this pendant World, nothing in nature is unbeautiful, silently as a dream the fabric rose, some touch of nature's genial glow, this majestical roof fretted with golden fire, through knowledge we behold the World's creation.

clockwork universe, closed universe, hub of the universe, island universe, universe of discourse