There are multiple origins and meanings for the name Agnes:
1. Comes from the ancient Greek word ἁγνός [agnos] - "clean, pure, righteous, chaste, innocent"
2. Derived from the Latin name (Agnus) meaning - "lamb". Lamb in Christianity - is a symbol of Jesus.
St. Agnes was a Roman girl who was only thirteen years old when she suffered martyrdom for her faith. Agnes had made a promise, a promise to God never to stain her purity. Her love for the Lord was very great and she hated sin even more than death! Since she was very beautiful, many young men wished to marry Agnes, but she would always say, "Jesus Christ is my only Spouse".