Lifting device that’s one among many (5)
I believe the answer is:
hoist
'lifting device' is the definition.
(hoist is a kind of lifting device)
'one among many' is the wordplay.
'one' becomes 'i' (Roman numeral).
'among' is an insertion indicator.
'many' becomes 'host' (I've seen this in other clues**).
'i' placed within 'host' is 'HOIST'.
'that's' is the link.
(Other definitions for hoist that I've seen before include "Winch" , "One that could raise" , "Raise with ropes" , "piece of lifting gear" , "I shot (anag)" .)