Green’s Dictionary of Slang

(S.Afr.) a political demonstrator.

1971		Rhodeo (Rhodes Univ.) 13 May 4: Love and kisses, all you blerrie betogers [DSAE].
1974		H. Levin Bandiet 217: The fault of ‘betogers’/demonstrators, long-haired demonstrators who were buggering up the tour with smoke-bombs and whistles and demos and everything.