Command in crossword erroneous (5)
I believe the answer is:
order
'command' is the definition.
(I know that order is a type of command)
'in crossword erroneous' is the wordplay.
'in' indicates the answer is hidden within the clue.
'ORDER' is hidden in the letters of 'crossword erroneous'.
(Other definitions for order that I've seen before include "Arrangement; command" , "Directive for harmony" , "Command, mandate" , "Apply for - class" , "Command; social class" .)