Organ that can go up or down? (3)
I believe the answer is:
eye
This clue is a double definition.
'organ' is the first definition.
(eye is a kind of organ)
'that can go up or down?' is the second definition.
(Other definitions for eye that I've seen before include "Organ of sight" , "'Public' or 'private' body part" , "Watch closely" , "Viewer" , "where the pupil is seated" .)