late 14c., "actual, solid; particular, individual; denoting a substance," from Latin concretus "condensed, hardened, stiff, curdled, congealed, clotted," figuratively "thick; dim," literally "grown together;" past participle of concrescere "to grow together," from assimilated form of com "together" (see con-) + crescere "to grow" (from PIE root *ker- (2) "to grow").

A logicians' term (opposed to abstract) until meaning began to expand 1600s (see concrete (n.)). Concrete poetry (1958), which depends much on the form or shape of its printing, is translated from terms coined independently in mid-1950s in Brazil (poesia concreta) and Germany (die konkrete Dichtung).

1520s, "that which is material or not abstract," a noun use of concrete (adj.). Meaning "a mass formed by concretion" is from 1650s, from the literal sense of Latin concretus. Hence "building material made from sand, gravel, stone chips, etc., cemented together" (1834). 

"to render (the abstract) concrete," 1826, from concrete (adj.) + -ize. Concrete itself sometimes was used as a verb in various senses from 1630s. Related: Concretized; concretizing.

c. 1600, "act of growing together or uniting in one mass;" 1640s, "mass of solid matter formed by growing together or conglomeration," from French concrétion (16c.) or directly from Latin concretionem (nominative concretio) "a compacting, uniting, condensing; materiality, matter," from concretus "condensed, congealed" (see concrete (adj.) ). Related: Concretional; concretionary.

Proto-Indo-European root meaning "to grow."

It forms all or part of: accretion; accrue; cereal; Ceres; concrete; create; creation; creature; Creole; crescendo; crescent; crew (n.) "group of soldiers;" croissant; cru; decrease; Dioscuri; excrescence; excrescent; griot; increase; Kore; procerity; procreate; procreation; recreate; recreation; recruit; sincere.

It is the hypothetical source of/evidence for its existence is provided by: Greek kouros "boy," korē "girl;" Latin crescere "come forth, spring up, grow, thrive, swell," Ceres, goddess of agriculture, creare "to bring forth, create, produce;" Armenian serem "bring forth," serim "be born."

also re-bar, "steel reinforcing rod in concrete," 1961, from re(inforced)bar (n.1).

of concrete, "formed by casting before being set in place," 1914; see pre- + cast (v.).

c. 1400, "swelling, bulging," from Latin extensionem/extentionem (nominative extensio/extentio) "a stretching out, extension," noun of action from past-participle stem of extendere (see extend). In a concrete sense, "extended portion of something" (a railroad, etc.), from 1852. Telephone sense is from 1906.