dimensionality UK /daɪˌmɛn.ʃəˈnæl.ɪ.tɪ/US /dɪˌmɛn.ʃəˈnæl.ə.tɪ/noun 2forms 1phrases 1 noun2 •The state or characteristic of possessing dimensions. •The number of dimensions something has.This often happens, for example, when a two-dimensional solution is obtained for data whose appropriate dimensionality is higher. — 1978 formsdimensionalities Phrases with dimensionality three-dimensionalityThe state or characteristic of occupying, or of appearing to occupy, three dimensions of space.