Origin: 1520–30; < Latin corrōborātus past participle of corrōborāre to strengthen, equivalent to cor-cor- + rōbor(āre) to make strong (derivative of rōbor, rōbur oak (hence, strength); see robust) + -ātus-ate1
early 16c., "to give (legal) confirmation to," from L. corroborat-, pp. stem of corroborare "to strengthen, invigorate," from cor- (see com-) "together" (perhaps here intens.) + roborare "to make strong," from robur, robus "strength," (see
robust). Meaning "to strengthen by evidence, to confirm" is from 1706. Sometimes in early use the word also has its literal Latin sense, especially of medicines. Related: Corroborated (1822); corroborating (1520s); corroborative (1580s).