Herein, we report the characterization of a novel germanium hydride radical arising from the photolysis/thermolysis of the diarylgermylene GeR2 [R = terphenyl: Ar-iPr4 = C6H3-2,6-(C6H3-2,6-Pr-i(2))(2) or Ar-iPr6 = C6H3-2,6-(C6H2-2,4,6-Pr-i(3))(2)] by using electron paramagnetic resonance spectroscopy complemented with theoretical calculations. The trapped germanium radical is a pseudoplanar S = 1/2 germanium(III) hydride, i.e., (GeHRR)-Ge-center dot' (R Ar-iPr4 = or Ar-iPr6; R' is a quaternary carbon), with a g tensor of [2.029, 2.003, 1.990], a Ge-73 hyperfine tensor of [-10, -90, -10] MHz, and a strong H-1 hyperfine tensor of [-23.0, -20.5, -31.5] MHz for the hydride. The germanium(III) hydride radical is a result of the insertion of a germanium(I) radical intermediate (:GeR) in a C-H bond, due to the greater reactivity of the germanium(I) radical intermediate in comparison with the tin(I) counterpart that we trapped earlier.