Illicit drawings German institute acquired after manipulating tariff (8)
I believe the answer is:
graffiti
'illicit drawings' is the definition.
'graffiti' can be an answer for 'drawings' (I've seen this before). I am not certain of the 'illicit' bit.
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for graffiti that I've seen before include "Alfresco wall art" , "Defacements on public walls" , "Wall scribblings" , "Wall scribbles" , "Drawing" .)