Run fluids into vessel (urn safest perhaps) (9)
I believe the answer is:
transfuse
'run fluids into vessel' is the definition.
I can't judge whether this defines the answer.
'urn safest perhaps' is the wordplay.
'perhaps' indicates an anagram.
'urn'+'safest'='urnsafest'
'urnsafest' with letters rearranged gives 'TRANSFUSE'.
Can you help me to learn more?
(Other definitions for transfuse that I've seen before include "Spread throughout" , "Safest run (anag.)" .)