Waveguide THz-TDS using metal parallel plate waveguides is employed to obtain a high-resolution terahertz vibrational spectrum of tris(hydroxymethyl)aminomethane, commonly known Lis Tris or THAM, an important biological buffer component, a neuroinhibitor and an organic thermal energy-storing Molecule. Dropcast and sublimated thin films are used to characterize the sample. The development (with cooling) of 3 broad resonances seen at room temperature into 12 highly resolved Spectral features for the dropcast sample and 11 features for a sublimated sample at 13.6 K is tracked by measuring the temperature dependence of the transmission spectrum. Resonances with fwhm linewidths Lis narrow as 12 GHz are obtained. These results provide strong constraints oil theoretical modeling.