ѳ

ѳ (upper case Ѳ)

1. A letter of the Cyrillic script, called fita.

ѳ (upper case Ѳ)

1. A letter of the Old Cyrillic script, called fita.

• 
  Regular.

ѳ • (f) (lower case, upper case Ѳ)

1. (obsolete) Letter fita (in Russian: фита́ f (fitá) or spelled ѳита́ f (fitá) before the 1917/1918 reform). Consonantal letter intended to represent the sound /θ/ but was replaced as /f/. Replaced by the letter ф (f) or т (t) in the spelling reform of 1917.

• This letter was normally used in Slavic words of Greek origin (though only for instances of /f/ that derived from Greek instances of /θ/). For example: orthography would be written as орѳогра́фія (orfográfija), Thebes would be written as Ѳивы (Fivy), etc.