Modest order hotel put in (6)
I believe the answer is:
chaste
'modest' is the definition.
(I've seen this before)
'order hotel put in' is the wordplay.
'order' becomes 'caste' (type of social rank or order).
'hotel' becomes 'h' (phonetic alphabet).
'put in' indicates putting letters inside (back).
'caste' enclosing 'h' is 'CHASTE'.
(Other definitions for chaste that I've seen before include "She-cat could be virtuous" , "Refraining from sex" , "Pure and decent" , "Everlasting" , "avoiding relations" .)