corroborant noun 2adjective 1forms 3 noun2 •(no longer used) Anything that gives strength or support; a tonic.Next to this it is imported to comfort the stomach, and to cherish the root of man, that is to say the brain, with its proper corroborants, especially with sweet odours and with music. — 1847 •(no longer used) Something that corroborates. adjective1 •(no longer used) strengthening; supporting; corroboratinga tonic has a corroborant effect formscorroborants · more corroborant · most corroborant