To stay in bed later than usual is right when one's tucked in (3,2)
I believe the answer is:
lie in
'to stay in bed' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for lie in that I've seen before include "Have an extended morning sleep" , "stay longer beneath the sheets" , "long sleep" , "Extended time in bed in the morning" , "Stay late in bed" .)