Useless houses occupied by a Zulu relative (5)
I believe the answer is:
xhosa
'zulu relative' is the definition.
(I've seen this in another clue)
'useless houses occupied by a' is the wordplay.
I cannot really see how this works, but
'by' could be 'x' (as in 'multiplied by') and 'x' is found within the answer.
'a' is found in the answer.
The remaining letters 'hos' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for xhosa that I've seen before include "South African language spoken with clicks" , "Tribesman" , "South African tribe" , "Cattle-rearer in South Africa" , "Member of a Bantu-speaking tribe" .)