(obsolete) The letterfita (Russianфита́(fitá)) orѳита́(fitá)). A consonantal letter intended to represent the Greek phoneme/θ/, which was approximated in Russian by/f/. Replaced by the letterф(f) in the spelling reform of 1917.
This letter was used in words ofGreek origin in cases where Russian/f/ derived from Greekθ(th) rather thanφ(ph). For example,орѳогра́фія(orfográfija,“orthography”),Ѳивы(Fivy,“Thebes”), etc.
In some words the pronunciation had changed to/t/ under French and German influence. These were accordingly replaced withт(t) instead ofф(f).