Moves slowly and carefully and steals all but the first (6)
I believe the answer is:
inches
'moves slowly' is the definition.
(I've seen this in another clue)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for inches that I've seen before include "Small islands" , "Twelve of them in a foot" , "Moves away; units of measurement" , "Slowly makes one's way" , "Islands; measurements" .)