Vocalism of the initial syllable is uncertain. Attested forms point to the reconstructions *cěsařь, *cesařь and *cьsařь. The first two are attested in OCS and CS. CS additionally contains attestations for cьsarь and carь in Russian, Serbian and Bulgarian Church Slavonic. The form *cьsařь has been explained as a common shortening of a form of address for persons; compare English king from Germanic *kuningaz, English miss from mistress.
Reflexes of *cěsařь are attested in the NW parts of Slavdom. The form *cesařь underpins the Western South Slavic forms, whereas the Bulgarian, Serbian and Russian CS forms reflect *cьsařь.
This variation could come from two reasons:
- the term was borrowed late, when Common Slavic had already begun disintegrating into different dialects
- the term was borrowed multiple times
Ultimately from Latin Caesar, the name of Julius Caesar, whose name became part of the Roman emperor's title. The name was very early borrowed into Germanic as *kaisaraz, whence it was borrowed into Slavic from an unknown source.
The most commonly regarded etymon cited in the literature is Gothic 𐌺𐌰𐌹𐍃𐌰𐍂 (kaisar), though such assignment is problematic. Old High German and Old Saxon forms with the suffix -ur are less plausible etymons. Formal mismatches with Gothic form include:
- Germanic short */a/ regularly yields */o/ in Common Slavic, and the reconstructions for the vowel suffix point to a short */a/. The regular suffix from the Gothic form would have been **-or.
- Even if we are dealing with analogical leveling to the productive agentive suffix *-āřь, this still doesn't fully explain the short vowel. The Slovene form points to a short suffixal vowel, since the accent retracted from short final vowels.
- If the short suffixal */-a-/ represents a late borrowing, after the Common Slavic rephonemicization of qualitative oppositions into quantitative ones, then this would exclude Gothic as the donor languages because the Goths lost their dominance in the Pontic region around the fifth century, well before such a process took place.
For forms *cěsařь and *cesařь:
- East Slavic:
- South Slavic:
- West Slavic:
- → Hungarian: császár
- Vasmer (Fasmer), Max (Maks) (1964–1973), “царь”, in Etimologičeskij slovarʹ russkovo jazyka [Etymological Dictionary of the Russian Language] (in Russian), volume III, translated from German and supplemented by Trubačóv Oleg, Moscow: Progress, page 283
- Saskia Pronk-Tiethoff (2013), The Germanic loanwords in Proto-Slavic, Rodopi: Amsterdam/New York, page 99ff
- Gluhak, Alemko (1993) Hrvatski etimološki rječnik (in Serbo-Croatian), Zagreb: August Cesarec, page 159
- Skok, Petar (1971) Etimologijski rječnik hrvatskoga ili srpskoga jezika (in Serbo-Croatian), volume I, Zagreb: JAZU, page 258f
- Sławski, Franciszek, editor (1976) Słownik prasłowiański (in Polish), volume II, Wrocław: Polska Akademia Nauk, page 82f
- Vykypěl, Bohumil (2011) Studie k šlechtickým titulům v germánských, slovanských a baltských jazycíc, Praha: Nakladatelství Lidové noviny, pages 117ff