What does trust mean to you in the context of submission?
Sweet, I always wanted to publish a book. Joking aside, I will try to be concise.
As a submissive, trust in my Domme is that she will act with the best interests of the relationship. I trust that she will care for my overall well-being. I trust that I will feel her love for me. I trust that she will reign me in if I get too deep. Life isn't perfect and there is a chance she will make mistakes, but as long as her intentions were good I am able to forgive and move on without losing trust.
Earning and maintaining her trust is equally important. She trusts that I will be open with her in all things. She trusts that I will be honest and communicate my thoughts and feelings. She trusts that I will put forth my best effort in serving her and focus on her happiness. She trusts that I will follow her instructions and not take advantage of my privileges and freedoms. She trusts that I will show my love for her every single day.