Optical absorption measurements are used to locate and assign 79 crystal-field (Stark) levels split out of the 4f3 electronic configuration of Nd3+ in single crystals of neodymium nonahydrate tris(trifluoromethanesulfonate), [Nd(H2O)9](CF3SO3)3, denoted hereafter as NdTRF. Line strengths are determined for 56 transitions between Stark levels. Single crystals of NdTRF have hexagonal, P63/m(C6h2) space-group symmetry, and each Nd3+ ion is coordinated to nine water molecules in a slightly distorted tri-capped trigonal prism structure of C3h symmetry. The energy-level structure of 4f3 (Nd3+) in NdTRF is analyzed in terms of a model Hamiltonian that includes consideration of both one-electron crystal-field and two-electron correlation-crystal-field interactions, the latter interactions making important contributions to the energy-level structures of several 4f3 [SL]J multiplet manifolds. Line strength data obtaibned for NdTRF is analyzed in terms of a general 4f → 4f transition intensity model in which the details of the 4f-electron/crystal-field/electric-dipolar radiation-field interactions are represented in parametric form. The derived parameters provide information about structural properties and interaction mechanisms that contribute to 4f → 4f transition intensities. The general crystal-field and intensity parameters are further analyzed in terms of a set of ‘intrinsic’ parameters that are related to contributions from individual Nd3+ OH2 pairwise interactions.