Stay in bed a bit longer – left, that is, at home (3,2)
I believe the answer is:
lie in
'stay in bed a bit longer aeur left that is at home' is the definition.
'lie in' can be an answer for 'stay in bed' (I've seen this before). I'm not sure about the rest of the definition.
'left that is at home' is the wordplay.
'left' becomes 'l' (common abbreviation).
'that is' becomes 'ie' (short for Latin 'id est', 'that is').
'at home' becomes 'in' ('I'm in' can mean 'I'm at home').
'l'+'ie'+'in'='LIE-IN'
Can you help me to learn more?
(Other definitions for lie in that I've seen before include "long sleep" , "Stay in bed, be a lazybones" , "Rise late" , "Extra time abed" , "Stay longer abed" .)