birch tar oil
Also found in: Medical.
birch tar oil
[′bərch ‚tär ‚ȯil] (materials)
A toxic liquid mixture of guaiacol, phenols, cresol, xylenol, and creosol; derived from distillation of birch tar and by dry distillation of the wood of Betula alba ; used as a disinfectant, in leather dressing, and in medicine.