tvьrdь

tvьrdь Grammatical information: f. i Proto-Slavic meaning: `citadel, firmament'

Old Church Slavic:

tvrьdь `base, citadel, firmament' [f i]

Russian:

tverd' `firmament (nebesnaja t.), earth (zemnaja t.)' [f i]

Old Russian:

tvьrdь `firmament, darkness' [f i]

Bulgarian:

tvărd (arch.) `citadel, earth, sky, firmament' [f i]

Indo-European reconstruction: turH-dʰ-i-