There are multiple origins and meanings for the name Agatha:
1. Ancient Greek name, derived (ἀγᾰθός) [agathos] etymology (definition) - "kind, good, good-natured; innocently, kindly"
2. Comes from the Latin word agathum meaning - "notable; precious (thing)".
St. Agatha One of the most highly venerated virgin martyrs of Christian antiquity, put to death for her steadfast profession of faith in Catania, Sicily. Although it is uncertain in which persecution this took place, we may accept, as probably based on ancient tradition, the evidence of her legendary life, composed at a later date, to the effect that her martyrdom occurred during the persecution of Decius (250-253).