[de.na.ture] vb de.na.tured ; de.na.tur.ing vt (1685) 1: dehumanize
2: to deprive of natural qualities: change the nature of: as a: to make (alcohol) unfit for drinking (as by adding an obnoxious substance) without impairing usefulness for other purposes b: to modify the molecular structure of (as a protein or DNA) esp. by heat, acid, alkali, or ultraviolet radiation so as to destroy or diminish some of the original properties and esp. the specific biological activity ~ vi: to become denatured -- de.na.tur.ant n -- de.na.tur.ation n