Green’s Dictionary of Slang

gek adj.

also gekke
[Du. gek, mad]

(S.Afr.) foolish, obsessed, insane.

‘Kaatje Kekkelbek or Life Among the Hottentots’ in D.C.F. Moodie Hist. Battles Adventures British, Boers etc. (1888) II 555: [At] school I learnt a kleine beetje, / But left it just as great a fool / As gekke Tante Meitje.