TRUST.....wat does it mean?

Really wat is the meaning of trust?
I've asked myself this question over and over again and I can't seem to find my answer.
It's troubling....I've had sleepless nights trynna find an answer to wat trust means to me...
Don't seem to understand y I have to trust someone to do stuff for me before it can be done.
Where do we draw the line and what do we do to help bring back da trust we once had for someone who hurt us real bad?
Still searching for an answer to this question and when I do I'll be happy to understand the meaning and depth of this word "TRUST"