A miniature model of something.

Roget 193: littleness etc. adj.; smallness etc. (of quantity) 32; exiguity, inextension^†; parvitude^†, parvity^†; duodecimo^†; Elzevir edition, epitome, microcosm; rudiment; vanishing point; thinness etc. 203.    dwarf, pygmy, pigmy^†, Liliputian, chit, pigwidgeon^†, urchin, elf; atomy^†, dandiprat^†; doll, puppet; Tom Thumb, Hop-o'-my-thumb^†; manikin, mannikin; homunculus, dapperling^†, cock-sparrow.    animalcule, monad, mite, insect, emmet^†, fly, midge, gnat, shrimp, minnow, worm, maggot, entozoon^†; bacteria; infusoria^†; microzoa [Micro.]; phytozoaria^†; microbe; grub; tit, tomtit, runt, mouse, small fry; millet seed, mustard seed; barleycorn; pebble, grain of sand; molehill, button, bubble.    point; atom etc. (small quantity) 32; fragment etc. (small part) 51; powder etc. 330; point of a pin, mathematical point; minutiae etc. (unimportance) 643.    micrometer; vernier; scale.    microphotography, photomicrography, micrography^†; photomicrograph, microphotograph; microscopy; microscope (optical instruments) 445.    ... show more

Dutch: microkosmos
Polish: mikroświat, mikrokosmos