Perhaps Medusa's taken for granted (7)
I believe the answer is:
assumed
'taken for granted' is the definition.
(synonyms)
'perhaps medusa's' is the wordplay.
'perhaps' indicates anagramming the letters.
'medusas' with letters rearranged gives 'ASSUMED'.
(Other definitions for assumed that I've seen before include "Affected; supposed" , "Fancied" , "Falsely adopted" , "Put it on - without being told?" , "Took (responsibility)" .)