is,

Softness of temper; mildness; gentleness; bearing injuries patiently.
Also,
Humility; submission to God's will without murmuring.
Being meek is the opposite of being proud or arrogant.

But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith, Meekness, temperance: against such there is no law. And they that are Christ's have crucified the flesh with the affections and lusts. If we live in the Spirit, let us also walk in the Spirit.
Galatians 5:22-25