Go up steps that may go up or down (5)
I believe the answer is:
scale
'go up' is the definition.
(scaling is a kind of going up)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for scale that I've seen before include "Part of fish/reptile skin" , "Deposit in kettles, etc" , "Weigh up" , "Series of notes in an octave" , "Graduated table" .)