By surface analysis, *pȗstъ (“desolate”) + *-ja.
*pušča f
singular | dual | plural | |
---|---|---|---|
nominative | *pušča | *pušči | *puščę̇ |
genitive | *puščę̇ | *pušču | *puščь |
dative | *pušči | *puščama | *puščamъ |
accusative | *puščǫ | *pušči | *puščę̇ |
instrumental | *puščejǫ, *puščǫ** | *puščama | *puščami |
locative | *pušči | *pušču | *puščasъ, *puščaxъ* |
vocative | *pušče | *pušči | *puščę̇ |
* -asъ is the expected Balto-Slavic form but is found only in some Old Czech documents; -axъ is found everywhere else and is formed by analogy with other locative plurals in -xъ.
** The second form occurs in languages that contract early across /j/ (e.g. Czech), while the first form occurs in languages that do not (e.g. Russian).