“expenditure” means net expenditure after taking into account any rebates or returns from expenditure, regardless of when such last-mentioned expenditure was incurred;

[Definition of “expenditure” subsitututed by section 21(d) of Act 65 of 1973 and amended by section 52(1)(b) of Act 15 of 2016 effective on 1 April, 2017 and applicable in respect of expenditure incurred during years of assessment commencing on or after that date]