I learnt to be trusting (7)
I believe the answer is:
reliant
'trusting' is the definition.
(synonyms)
'i learnt to be' is the wordplay.
'to be' is an anagram indicator.
'i'+'learnt'='ilearnt'
'ilearnt' is an anagram of 'RELIANT'.
(Other definitions for reliant that I've seen before include "Robin was one < in need of support" , "Depending (upon)" , "Dependent upon" , "leaning" , "Inspiring confidence" .)