Small island's lifting gear has top missing (4)
I believe the answer is:
inch
'small island's' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for inch that I've seen before include "Not very far" , "Creep - a very short distance" , "Imperial measure" , "0.0254 metre" , "25.4 millimetres" .)