Communicate what wrong answer may do (3,6)
I believe the answer is:
get across
'communicate' is the definition.
(thesaurus)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for get across that I've seen before include "what crucifer must do first of all" , "Communicate successfully" , "Go over - explain" , "go over viaduct, say" , "Express" .)