Blockage of some limb, possibly (8)
I believe the answer is:
embolism
'blockage' is the definition.
(thesaurus)
'some limb possibly' is the wordplay.
'possibly' is an anagram indicator.
'some'+'limb'='somelimb'
'somelimb' anagrammed gives 'EMBOLISM'.
'of' is the link.
(Other definitions for embolism that I've seen before include "Arterial obstruction" , "Blood vessel blockage" , "obstructive clot" , "Obstruction of artery by blood clot" , "Obstruction of a blood vessel as by clot or bubble" .)