Guidelines smooth lecturer entered… (3,3,5)
I believe the answer is:
dos and donts
'guidelines' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.
'smooth lecturer entered' is the wordplay.
I cannot quite understand how this works, but
'smooth' could be 'sand' (sanding is a kind of smoothing) and 'sand' is found in the answer.
'lecturer' could be 'don' (don can mean an academic) and 'don' is found in the answer.
The remaining letters 'dots' 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?
(Another definition for dos and donts that I've seen is " Rules of behaviour".)