Safavi

Safavi is an adjective, created for the name "Safi". Translated to English, "Safavi" would correspond roughly to "Safi-ish" or "Safidian"

"Safavi" is the correct Persian language reference to "Safi", the name of Sheikh Safi Al-Din Ardebili. Similarly we speak of "Edwardian", when making a reference to the era affiliated with king Edward. Sheikh Safi's descendants have been going by this name for 770 years. There are numerous bearers of the name "Safavi" thriving in modern day Iran, who claim descent from Sheikh Safi or any of his royal heirs.

The term "Safavid", as in Safavid Dynasty (of which Sheikh Safi is the Eponym), is likewise referred to as "Safavi" by Persian speakers. The "d" at the end of "Safavid" was added by the principle of analogy with the Greek-derived names of several ancient dynasties, such as the Achaemenid dynasty and the Sassanid dynasty, based on the oblique cases of the Greek names. The English adjective "Safavid" and the name "Safavids" for the dynasty, and the corresponding forms in many European languages, are therefore based on a redundant application of adjective-forming rules.

The names "Safavid/Safavids" are well-established in the English language, however, and have become legitimate terms. When added to a Shah's name however, the original "Safavi", without the "d" at the end, must always be retained, e.g., Shah Ismail I Safavi.