According to what is heard, lazy pupils practise hero worship (7)
I believe the answer is:
idolise
'worship' is the definition.
(I know that worship can be written as idolise)
'according to what is heard lazy pupils practise hero' is the wordplay.
I cannot really understand how this works, but
'is' is within the answer.
'practise' could be 'do' (synonyms) and 'do' is located in the answer.
The remaining letters 'ile' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for idolise that I've seen before include "Make into a figure of worship" , "Revere, love greatly" , "Doilies to worship" , "Pay excessive attention to" , "Love too much" .)