Renovated castle, keeping area or moving staircase? (9)
I believe the answer is:
escalator
'moving staircase?' is the definition.
(synonyms)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for escalator that I've seen before include "effortless steps" , "Carol eats (anag.)" , "nonstop flight" , "the easy way up" , "financial clause" .)