A clot is treated for patient (7)
I believe the answer is:
stoical
'patient' is the definition.
(thesaurus)
'a clot is treated' is the wordplay.
'treated' indicates an anagram.
'a'+'clot'+'is'='aclotis'
'aclotis' anagrammed gives 'STOICAL'.
'for' is the link.
(Other definitions for stoical that I've seen before include "able to endure suffering" , "Uncomplaining in the face of adversity" , "Impassive" , "Seeming to be unaffected by pleasure or pain" , "Long-suffering" .)