c. 1400, consolidacioun, "act of making or process of becoming solid or firm," of wounds, broken bones, etc., from Late Latin consolidationem (nominative consolidatio), noun of action from past participle stem of consolidare "to make firm, consolidate," from assimilated form of com "with, together" (see con-) + solidare "to make solid," from solidus "firm, whole, undivided, entire," from suffixed form of PIE root *sol- "whole." Meaning "act of bringing together and uniting different parts into one body or whole" is from 1670s.