Merriam-Webster Collegiate Dictionary - concrete

 I. adjective  Etymology: Middle English, from Latin concretus, from past participle of concrescere  Date: 14th century  1. naming a real thing or class of things the word poem is ~, poetry is abstract  2. formed by coalition of particles into one solid mass  3.  a. characterized by or belonging to immediate experience of actual things or events  b. specific, particular a ~ proposal  c. real, tangible ~ evidence  4. relating to or made of ~ a ~ wall  • ~ly adverb  • ~ness noun  II. verb  (~d; concreting)  Date: 1590  transitive verb  1.  a. to form into a solid mass ; solidify  b. combine, blend  2. to make actual or real ; cause to take on the qualities of reality  3. to cover with, form of, or set in ~  intransitive verb to become ~d  III. noun  Date: 1656  1. a mass formed by concretion or coalescence of separate particles of matter in one body  2. a hard strong building material made by mixing a cementing material (as portland cement) and a mineral aggregate (as sand and gravel) with sufficient water to cause the cement to set and bind the entire mass  3. a waxy essence of flowers prepared by extraction and evaporation and used in perfumery