Any material used to thicken:
— Starch is used in cooking as a thickening.

synonym: thickener.

Dutch: bindmiddel, temper, verdikkingsmiddel
Polish: zagęszczacz

Any thickened enlargement.

synonyms: knob, node.

The act of thickening.

synonym: inspissation.

Roget 352: semiliquidity; stickiness etc. adj.; viscidity, viscosity; gummosity^†, glutinosity^†, mucosity^†; spissitude^†, crassitude^†; lentor^†; adhesiveness etc. (cohesion) 46.    inspissation^†, incrassation^†; thickening.    jelly, mucilage, gelatin, gluten; carlock^†, fish glue; ichthyocol^†, ichthycolla^†; isinglass; mucus, phlegm, goo; pituite^†, lava; glair^†, starch, gluten, albumen, milk, cream, protein^†; treacle; gum, size, glue (tenacity) 327; wax, beeswax.    emulsion, soup; squash, mud, slush, slime, ooze; moisture etc. 339; marsh etc. 345.    ... show more

Roget 321: density, solidity; solidness etc. adj.; impenetrability, impermeability; incompressibility; imporosity^†; cohesion etc. 46; constipation, consistence, spissitude^†.    specific gravity; hydrometer, areometer^†.    condensation; caseation^†; solidation^†, solidification; consolidation; concretion, coagulation; petrification etc. (hardening) 323; crystallization, precipitation; deposit, precipitate; inspissation^†; gelation, thickening etc. v.. indivisibility, indiscerptibility^†, insolubility, indissolvableness.    solid body, mass, block, knot, lump; concretion, concrete, conglomerate; cake, clot, stone, curd, coagulum; bone, gristle, cartilage; casein, crassamentum^†; legumin^†.    superdense matter, condensed states of matter; dwarf star, neutron star.    ... show more

Polish: gęstnienie, gęstnięcie

Accumulating and becoming more intense:
— The thickening dusk.

synonym: deepening.

Becoming more intricate or complex.