Thesalonian or Thessalonian: How To spell?
The word Thesalonian is misspelled against Thessalonian, a noun meaning "A native or inhabitant of Thessalonica."
Thessalonian has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings the & alonian which should not be misspelled with single 'S'
Wrong Spelling:  the-s-alonian  Correct Spelling:  the-ss-alonian 
Find more incorrect spellings of Thessalonian to spell right way.