What does it mean to be humble?

Humble is defined as not being arrogant or proud, but also being subservient. It is an interesting concept because if we are truly humble we cannot lay claim to being humble since the claim itself would be prideful.
So being humble would be a state of living that permeates our entire life. If we remove our pride and arrogance from our lives and live a life intentionally in service too others, then how much easier would it be to live the following verse.
Ephesians 4:2 Be completely humble and gentle; be patient, bearing with one another in love.
If we live this way then surely it would follow.
Psalm 147:6 The Lord sustains the humble but casts the wicked to the ground.