Poorly Neil entertains one stay in bed (3-2)
I believe the answer is:
lie-in
'stay in bed' is the definition.
(I've seen this before)
'poorly neil entertains one' is the wordplay.
'poorly' indicates anagramming the letters (a poor spelling).
'entertains' indicates putting letters inside.
'one' becomes 'i' (Roman numeral).
'neil' is an anagram of 'lien'.
'lien' going around 'i' is 'LIE-IN'.
(Other definitions for lie-in that I've seen before include "Period in bed longer than usual" , "Extended sleep" , "Extra snoozing" , "time spent with crossword, perhaps" , "Extra time in bed" .)