A novel photonic crystal fiber in quasi pattern (Q-PCF) is designed and proposed for terahertz wave (T-wave) guidance. A cyclic olefin copolymer (COC) has been used as the bulk material of the proposed fiber. The proposed Q-PCF is introduced here for T-wave propagation, scaling from 0.8 to 2.40 THz. It is noted that, a low effective material loss (EML) of 0.038 cm⁻¹ is obtained at working frequency f = 1 THz. It leads to a reduction in bulk absorption loss of 81% at the same working frequency. Moreover, some essential optical guiding parameters such as confinement loss, dispersion, modality, power fraction and effective mode area are also examined briefly. The fabrication of the proposed PCF is simple as it contains only air holes of circular shape. It is anticipated that the mentioned Q-PCF terahertz waveguide will provide a significant improvement over existing designs.