I think a decent general definition, for real people, might be "disinformation something someone else did not want you to know." It might be true or not, but they were counting on you following some different narrative.
everything is propaganda, to some degree: no one went to the effort of telling you $X without they thunk they was gonna benefit from you hearing it. You have to take that into account with everything. "Advertising" is a more acceptable name, perhaps; but the bare facts of it haven't changed since someone was attempting to talk someone else into supplying the livestock for a BBQ party "for the greater glory of $gods"