Pay no attention to piece of instruction, e.g. lecture (7)
I believe the answer is:
neglect
'pay no attention to' is the definition.
(thesaurus)
'of instruction e g lecture' is the wordplay.
'of' indicates a hidden word.
'NEGLECT' is hidden in the letters of 'instruction e g lecture'.
'piece' acts as a link.
(Other definitions for neglect that I've seen before include "lack of concern?" , "Failure to show care" , "Insufficiently attend to" , "Failure to give proper care" , "Fail to take proper care of, be derelict" .)