Foster may run true to form (7)
I believe the answer is:
nurture
'foster' is the definition.
(synonyms)
'run true to form' is the wordplay.
'to form' indicates an anagram.
'run'+'true'='runtrue'
'runtrue' anagrammed gives 'NURTURE'.
'may' acts as a link.
(Other definitions for nurture that I've seen before include "Sustain" , "Encourage to develop" , "Feed - support" , "Cherish (an ambition)" , "Bring up" .)