Green’s Dictionary of Slang

(S.Afr.) crazy, forgetful, eccentric.

[1710		Rouxel & Halma Grand Dictionaire François et Flamend 383/1: Loskop, Tète écervelée].
1977		letter 19 Apr. in J. & W. Branford Dict. S. Afr. Eng. (1987) 181: Please accept my apologies with a solemn undertaking not to be so loskop next time.