Religious woman going up and down (3)
I believe the answer is:
nun
I believe this is a double definition.
'religious woman' is the first definition.
(woman who has taken religious vows)
'going up and down' is the second definition.
(Other definitions for nun that I've seen before include "Domestic fancy pigeon" , "A palindromic holy woman" , "Mother Superior, perhaps" , "She's a member of a religious community" , "Letter" .)