The Collaborative International Dictionary of English v.0.48:

dagga \dagga\ n.
   a relatively nontoxic South African herb (Leonotis
   leonurus) smoked like tobacco.

   Syn: Cape dagga, red dagga, wilde dagga, Leonotis leonurus.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

dagga
    n 1: relatively nontoxic South African herb smoked like tobacco
         [syn: dagga, Cape dagga, red dagga, wilde dagga,
         Leonotis leonurus]