There are multiple origins and meanings for the name:
1. Derived from the Latin word gratus meaning - "pleasant, attractive, cute; dear, beloved; grateful, thankful"
2. German form of the personal name Grace/Gratia - "grace".
St Grata was one of the 48 Martyrs of Lyons (177 AD). Also with her martyred at this time were: Blandina, Photinus, Zacharias, Epagatus, Macarius, Alcibiades, Silvius, Primus, Ulpius, Vitalis, Cominus, October, Philuminus, Geminus, Iulia, Albina, Rogata, Oemilia, Potamia, Pompeia, Rhodana, Biblis, Quartia, Materna, Helpes, Sanctus, Maturus, Attalus, Alexander, Ponticus, Arisceus, Cornelius, Iosinus, Titus, Ivlius, Zoticus, Apollonius, Geminianus, Ivlia, Auzonia, Cemlia, Jamnica, Domna, Iusta, Trophima and Antonia.