integration n.

1630s, "to render (something) whole, bring together the parts of," from Latin integratus, past participle of integrare "make whole," from integer "whole, complete," figuratively, "untainted, upright," literally "untouched," from in- "not" (see in- (1)) + root of tangere "to touch," from PIE root *tag- "to touch, handle."

The meaning "put together parts or elements and combine them into a whole" is from 1802. The "racially desegregate" sense (1940) probably is a back-formation from integration. Related: Integrated; integrating.

1550s, "act of separating" (a sense now obsolete); 1610s, "act or action of segregating, separation from others," from Late Latin segregationem (nominative segregatio), noun of action from past-participle stem of segregare (see segregate). Meaning "state or condition of being segregated" is from 1660s. Specific U.S. sense of "enforced separation of races" is attested from 1883.