Korinthenkacker
nitpicker, hair-splitter, pedant (derogatory colloquial)
Origin
Crudely jocular and derogatory for a pedantic, petty person who fixates on the tiniest details and takes everything overly precisely. Formed from 'Korinthe' (a small dried grape/currant), a linking 'n', and the vulgar 'Kacker'. The image: someone who scrutinises even the smallest currant one by one.
Building blocks
Words in this expression
Examples
Muss das sein, du Korinthenkacker?
Is that really necessary, you nitpicker?