Thessalonians
noun
Thes·sa·lo·nians ˌthe-sə-ˈlō-nyənz 
-nē-ənz
plural in form but singular in construction
: either of two letters written by St. Paul to the Christians of Thessalonica and included as books in the New Testament see Bible Table
Word History
Etymology
Thessalonian inhabitant of ancient Thessalonica, irregular from Thessalonica
First Known Use
1636, in the meaning defined above