This root
-mir has become with time just a formal element added to various stems and producing, especially in South Slavic languages, diverse and sometimes bizarre outcomes.
In the earliest East Slavic texts, we find the following.
Old Novgorod dialect —
Зализняк АА · 2004 · ‹Древненовгородский диалект›: 838, 204 (for unknown reasons given in their southern East Slavic forms, not in the shape they actually had in that dialect):
Tvorimirъ
Sutimirъ
Vidomirъ
Žiznomirъ
Jaromirъ
Solьmirъ (from *Solimirъ ? — p. 69)
Stanimirъ~Stanьmirъ
Ratьmirъ (from *Ratimirъ ? — p. 69, 468) — Old Polish has Racimiar<*Ratiměrъ (p. 468)
Also
Ostromirъ
General older East Slavic (with some Polish) —
Литвина АФ, Успенский ФБ · 2006 · ‹Выбор имени у русских князей в Х–ХVI вв. Династическая история сквозь призму антропонимики›:
Boremir
Vladimir~Vladimer~Volodimir~Volodimer
Vsevolodimer
Zvenimir
Kazimir
Stanimir
Tvorimir
Xotemir
Jaromir
Thus:
(1) the absolutely prevailing form on the East Slavic ground is -mirъ,
(2) the meanings are quite diverse and often not explicable from “world, peace”, e. g. Ostromirъ “Sharp-world/peace?”, Vidomirъ “Aspect-world/peace?”, Žiznomirъ “Life-world/peace?”, Ratьmirъ “Army-world/peace?”, Zvenimir “Ringing-world/peace?”. In all these cases the meaning “glorious, famous” is preferable, especially since parallel names in -slavъ exist for some (Jaromirъ — Jaroslavъ, Stanimirъ — Stanislavъ, Vladimirъ — Vladislavъ, Zvenimir — Zvenislava [woman]).
Across Slavic,
mirъ “peace, world” coexists with *
měrъ ‘the same’ (
‹Этимологический словарь славянских языков…› — ‹Выпуск 19 (męs(’)arь-morzakъ)› · 1992 · ОН Трубачёв: 55–57): dialectal Serbo-Croatian
mijer, Old Czech
mier, Slovak
mier. So, one may have explained the alternation
-mirъ~-měrъ in these names from the purely Slavic material if not the third variant,
-merъ, which cannot be etymologically related (as
i and ě come from an
i-diphthong, which cannot have produced
e in the Slavic languages of the turn of the 1st and 2nd millennia).
In Germanic, we find the adjective
*mēraz “great, excellent; famous”. Its
o-grade counterpart exists in Celtic (
*māros, with similar compounds:
Iantumaros) and perhaps in Greek (
ἐγχεσίμωρος “famous for his spear” ? —
Beekes RSP · 2010 · ‹Etymological dictionary of Greek›: 372). In Slavic, it should have corresponded to
-měrъ and
-marъ, the latter unattested, and then both
-mirъ and
-merъ hang in the air.
So, the most probable explanation appears to me as follows. Indo-European languages once possessed personal names with the second element
*-mēros or
-mōros meaning something like “famous for”. These survived to historical times in Gaulish and especially in Germanic. Slavic probably lost them at some point or preserved as opaque historical remnants that speakers tried to re-analyze. The East Germanic dominance in the pre-Hunnic times (
Oium) made the Slavs acquainted with names in
*-mēr->*-mīr- (e. g. perhaps
Filimer; the shift
ē>ī was occurring in East Germanic precisely in those centuries and is well attested in names and as scribal errors) that were loaned in both phonetic variants, with
*ē>ě and
*ī>i. -
Merъ probably reflects the Greek pronunciation of these Germanic names borrowed somewhat later, when Slavs settled in what is now Bulgaria (
Thracian Goths).
P. S.
Vladikavkaz and
Vladivostok are artificial 19th century names given after that folk interpretation of
Vladimir as “rule the world”.