Trust, in this case, is the ability of two entities to believe that each other will be honest and genuine.
And how would you define an 'honest' person? May be someone you can trust!?

Every definition should include more basic terms than those it is trying to define. IMHO, 'honesty' is a more complex term than 'trust'! Almost every thief I've met with thinks they steal from their victims in an honest fashion.