Relaxation dynamics of low molecular glass-forming liquid triphenylomethane triglycidyl ether was studied under isothermal and isobaric conditions using dielectric spectroscopy. In addition we also carried out pressure-volume-temperature, PVT, measurements. The data enable us to examine the relaxation rate as functions of temperature, pressure and volume. Among other observed properties, it was found that temperature dependence of the alpha -relaxation times in vicinity of glass transition exhibit non-Arrhenius behavior even at constant volume conditions. Our findings confirm the thesis postulated by M. L. Ferrer and co-workers in J. Chem. Phys. 109, 8010 (1998) that temperature is a dominant control variable, which is responsible for the spectacular non-Arrhenius increase of relaxation rate near T-g. The pressure dependence of the glass transition temperature has also been determined both from dielectric and volumetric data. Satisfactory agreement between results obtained from the two methods has been found.