WordNet sense 1 (process or result of distributing or extending over a wide expanse of space):

spread

WordNet sense 2 (the opening of a subject to widespread discussion and debate):

airing, dissemination, public exposure

WordNet sense 3 (spreading by diffusion):

diffusive, scattering, diffusing, dispersive, disseminating, disseminative

WordNet sense 4 (serving to distribute or allot or disperse):

distributive