One of the old people with a refusal in the morning to get up (5)
I believe the answer is:
mayan
'one of the old people' is the definition.
(the Mayans were an ancient people)
'with a refusal in the morning to get up' is the wordplay.
'with' means one lot of letters go next to another.
'a refusal' becomes 'nay' (I've seen this before).
'in the morning' becomes 'am'.
'to get up' says the letters should be written backwards.
'nay' next to 'am' is 'nayam'.
'nayam' written backwards gives 'MAYAN'.
(Other definitions for mayan that I've seen before include "Mexican native" , "Cent. American tongue" , "Central American Indian language" , "of a bygone civilisation" , "Relating to a people of Central America" .)