Hindrance making a Celt sob, possibly (8)
I believe the answer is:
obstacle
'hindrance' is the definition.
(I know that obstacle is a type of hindrance)
'a celt sob possibly' is the wordplay.
'possibly' is an anagram indicator.
'a'+'celt'+'sob'='aceltsob'
'aceltsob' anagrammed gives 'OBSTACLE'.
'making' is the link.
(Other definitions for obstacle that I've seen before include "Progress blocker" , "Barrier or impediment" , "stumbling block" , "It obstructs or hinders" , "difficulty" .)