Correct spelling for the English word "Thersa" is [ðˈɜːsə], [ðˈɜːsə], [ð_ˈɜː_s_ə] (IPA phonetic alphabet).
The name "Theresa" or "Thersa" is of Greek origin. It is derived from the Greek name Θερσα (Thersa), which was the name of a Greek island in the Aegean Sea. The exact meaning of the name is uncertain, but it is often theorized to mean "reaper" or "harvester" in Greek. Over time, the name Thersa evolved into various forms in different languages, including Teresa in Spanish and Italian, Teresia in Swedish, and Thérèse in French.