'corroborate' originates from Latin, specifically the word 'corroborare' (past participle 'corroboratus'), where the prefix 'com-/cor-' meant 'together/with' and 'roborare' meant 'to strengthen' (from 'robur' meaning 'strength, oak').

'corroborare' (Latin) passed into Late Latin/Medieval Latin as 'corroboratus' and entered English in the early 17th century as 'corroborate', retaining the sense of making strong or giving strength (in a figurative sense).

Initially, it meant 'to make strong' (literally or figuratively); over time it evolved to the more specific modern sense 'to support or confirm (a statement or theory) by providing evidence.'