The 2p3d resonant inelastic x-ray-scattering spectra of Ho2O3 are measured under 0.7 eV resolution and analyzed in terms of an equation based on the Kramers-Heisenberg formula. Broadening due to core-hole lifetime (4.26 eV) is completely suppressed to give sharp absorption bands with width of <0.5 eV together with energy position uncertainty ∼0.3 eV. Observed bands are assigned to be well-known 2p→4f quadrupolar transitions that are otherwise buried under lifetime-broadened intense 2p→5d dipole transition. The present work opens up an opportunity to study 4f-5d interactions more accurately.