Two centuries back, hotel becoming nick (5)
I believe the answer is:
notch
'nick' is the definition.
(both can mean a small cut or impression)
'two centuries back hotel' is the wordplay.
'two centuries' means two replacements for 'century'.
'century' becomes 'C' (common abbreviation).
'century' becomes 'ton' (both can mean one hundred of something).
'back' shows that the letters should be reversed in order.
'hotel' becomes 'h' (phonetic alphabet).
'c'+'ton'='cton'
'cton' back-to-front is 'notc'.
'notc'+'h'='NOTCH'
'becoming' is the link.
(Other definitions for notch that I've seen before include "Point or degree in a scale" , "Nick made in something as a record" , "Dent" , "Incision; indentation" , "Secure" .)