Confused earl, a Scot, using moving staircase (9)
I believe the answer is:
escalator
'moving staircase' is the definition.
(synonyms)
'confused earl a scot' is the wordplay.
'confused' indicates anagramming the letters.
'earl'+'a'+'scot'='earlascot'
'earlascot' anagrammed gives 'ESCALATOR'.
'using' is the link.
(Other definitions for escalator that I've seen before include "nonstop flight" , "Moving stairs" , "effortless steps" , "financial clause" , "Moving staircase" .)