Ultimate cobbler's tool (4)
I believe the answer is:
last
I believe this clue is a double definition.
'ultimate' is the first definition.
(similar in meaning)
'cobbler's tool' is the second definition.
(I've seen this in another clue)
(Other definitions for last that I've seen before include "Latest" , "` `The cobler should stick to his ....' '" , "model of repair" , "The cobbler's equipment will endure" , "nowhere near winning Miss World?" .)