Rather than defining faith in this setting let us describe it.
Faith is like being blindfolded while someone else who knows where the chair is guides you verbally to it so you know where to sit. Finally you reach the chair with their guidance and you sit. Faith is not a blind leap into nothing hoping that there might be a chair there. It is trusting that what some one else has told you is true and having taken them at their word you come to find out for yourself it is indeed true.
This is why faith breeds more faith.
This illustration also reminds us that we cannot exercise godly faith entirely on our own. You cannot rest or lean on something all in your own effort. We don’t get to that resting place in God by our own initiative or by our effort.
Thus, faith in the biblical sense is not a full exercise of your will, but the acceptance that what God has willed is incontrovertibly true. There cannot be true lasting rest if it’s left up to my own faith to decide where to find it and how to get and keep it.
Faith is what God gives you to help you find Him.