Quote Originally Posted by Mig25 View Post
I manage to find that this is some sort of old russian word for city..
Not Old Russian, but Old Church Slavonic.

In Old Russian, on the contrary, it’s always -оро-, -оло-, not -ра-, -ла-, -ре-, -ле-.
Old Russian is pleophonic like all other East Slavic Languages, while Old Church Slavonic being a South Slavic language is non-pleophonic.

In contemporary Russian, Old Russian forms and Church Slavonic ones are mixed together. During many centuries, Church Slavonic was a literary language in Russia, and Russian language borrowed a lot from it.

There are many Russian—Church-Slavonic doublet words in contemporary Russian.

Sometimes, the Church Slavonic word is a poetic variant of a Russian word:

Russian Church Slavonic
го́род (standard) град (poetic)
зо́лото (standard) зла́то (poetic)
воро́та (standard) врата́ (poetic)

Sometimes, the way around:

Russian Church Slavonic
во́рог (poetic) враг (standard)
шело́м (poetic) шлем (standard)

Sometimes, the two are synonyms, or words with close meanings, or even with completely different meanings:

Russian Church Slavonic
рожа́ть ‘give birth’ рожда́ть ‘give birth, give rise, create’
горожа́нин ‘town/city dweller’ граждани́н ‘sitizen; sir’
голова́ ‘head’ глава́ ‘chief; chapter’
горя́чий ‘hot’ горя́щий ‘burning’
сторона́ ‘side’ страна́ ‘country’
по́рох ‘gunpowder’ прах ‘ashes, remains’
хорони́ть ‘bury’ храни́ть ‘keep, store’
нёбо ‘palate’ не́бо ‘sky’

Church Slavonic variants are used actively in word formation and calques due to their brevity even if the Church Slavonic word is not used by its own:

word with a Russian root derivate with a Church Slavonic root
де́рево ‘tree; wood’ древе́сный ‘arboreal’
го́лос ‘voice’ гла́сность ‘publicity’
хо́лод ‘cold’ хладосто́йкий ‘cold-resistant’
молоко́ ‘milk’ млекопита́ющее ‘mammal’