The layered NaMnO2 is challenging as it is an experimental realization of a two-dimensional spin-2, spatially anisotropic triangular lattice, where the interplay of temperature and strong conflicting interactions, stimulates a remarkable inhomogeneous magnetic ground state. The proposed neutron diffraction experiment will utilize a single crystal specimen that has recently been grown at Warwick to study how the ground state degeneracy of NaMnO2 is lifted. The unusual short-range order that precedes the low-temperature transformation to an antiferromagnetic state and its coexistence with low-dimensional magnetic correlations will be studied to allow a greater insight on the origin of inhomogeneity. Subsequently, its sensitivity to small perturbations that could favor certain states among the degenerate ground-state manifold, will be investigated by a moderate external magnetic field.